HIGH-Tc UPDATE E-MAIL VERSION, VOL. 14, NO. 4, Feb. 15, 2000.
<p>
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 <hr>
<p>
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<p>
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<p>
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<p>
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<p>
 NOTA BENE:
<p>
 Dear Readers:
<p>
 This is to let you know that High-Tc Update newsletter will cease
 publication with the April 15 issue. This will complete 13 full years
 of the newsletter's existence. It has been an incredible journey, full
 of surprises and wonder. The Web site
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 will both attend the M^2S Conference in Houston next week, and will be
 happy to reminisce about High-Tc Update with anyone interested!
<p>
 Sincerely,
 Sreeparna Mitra
 (Editor)
<p>
 <hr>
<p>
 Films
<p>
 A recent paper by B. Dam et al. (Amsterdam) [Nature 399, 439 (1999)]
 presented evidence that at low temperatures dislocations are the
 dominant flux-pinning centers in laser-ablated thin films of YBa2Cu3O7-d
 deposited on (100) SrTiO3 substrates. (See also Nota Bene item in the
 September 15, 1999, issue of High-Tc Update.) A related preprint by J.
 M. Huijbregtse et al. (Amsterdam) concludes that the pinning is due to
 dislocations formed at the substrate-film interface. The authors found
 that they could tune the dislocation density over two orders of
 magnitude (~1-100 micrometers^[-2]) by varying the substrate temperature
 or by depositing a layer of Y2O3 precipitates before starting the
 YBa2Cu3O7-d growth process. In contrast to the artificial columnar
 defects in bulk created via heavy-ion irradiation, strong-pinning linear
 defects in thin films show a nonrandom spatial distribution. The radial
 dislocation distribution function was found to approach zero at small
 distances, indicating short-range ordering of the defects.
<p>
 As noted in a preprint by C.-Y. Yang (Wisconsin-Madison) et al., the
 deposition of chemically and structurally optimized epitaxial oxide
 films onto inexpensive biaxially textured substrates may well be a key
 to the manufacture of practical high-Tc superconductor cable for power
 applications. The authors point out that chemical solution
 heteroepitaxy is a nonvacuum, relatively simple technique that is
 readily scalable to production quantities. The preprint describes the
 properties of a YBa2Cu3O7-d (YBCO) film grown on a solution-deposited
 NdGaO3 (NGO) buffer layer on (100) SrTiO3 (STO). The 25-nm-thick NGO
 buffer layer was dip-coated onto the STO single crystal from a solution
 of metal methoxyethoxides in 2-methoxyethanol. Pulsed-laser deposition
 (PLD) was used to grow a 250-nm-thick YBCO film on the NGO. The x-ray-
 diffraction phi- and omega-scans indicated that the YBCO film was highly
 oriented with a full width at half maximum peak breadth of 1.14 degrees
 for in-plane and 0.46 degree for out-of-plane alignment. The transport
 critical current density Jc was found to be 1 x 10^6 A/cm^2 (77 K, 0 T).
 The authors conclude that buffer layers grown by solution synthesis are
 viable templates for YBCO growth and that this technique shows promise
 for the future of coated conductors in technology.
<p>
 Epitaxial thin films of YBCO have been deposited on yttria-stabilized
 zirconia (YSZ) by J. Gao (Hong Kong) et al. using PLD. The authors
 found that the initial epitaxy of YBCO thin films grown on YSZ can be
 significantly improved by using La2-xSrxCuO4 (LSCO) as a buffer layer.
 The x-ray-diffraction measurements showed that the epitaxial YBCO had a
 single in-plane orientation with YBCO [100] || LSCO[100] || YSZ O110].
 Real-time resistance measurements revealed that with LSCO buffer layers
 the initial formation of the YBCO ultra-thin films changes from island
 growth to layer-by-layer growth.
<p>
 The effect of compressive epitaxial strain induced in (001)-oriented
 La2-xSrxCuO4 (LSCO) and La2-xBaxCuO4 (LBCO) thin films on LaSrAlO4
 substrates has been studied by H. Sato (NTT) et al. The authors found
 that the superconducting transition temperatures Tc of these films
 reached 44 K and 47 K, respectively, with d ~~ 0. When both films had d
 > 0, Tc reached 49K, higher than the values for bulk samples. Noting
 that films with lower residual resistivity have higher Tcs, the authors
 speculate that the Tc enhancement is caused by reduced antiferromagnetic
 spin fluctuations in the CuO2 planes due to changes in the Cu-O_[apex]
 (copper-apical oxygen) bond length.
<p>
 A preprint by M. Sato et al. (SRL-ISTEC) reports on well-characterized
 a-axis trilayers made of NdBa2Cu3O7-d and PrBa2(Cu,Co)3O7-d films with
 smooth surface morphology and high crystallinity. The thin films were
 grown on (100) SrTiO3 (STO) substrates by rf + dc hybrid sputtering.
 Planar junctions fabricated from these trilayers exhibited Josephson
 current and well-developed Shapiro steps under 7-20 GHz microwave
 radiation. The current-voltage characteristics were qualitatively
 consistent with the resistively shunted junction (RSJ) model.
<p>
 As noted by Y. Li et al. (SRL-ISTEC), successful fabrication of high-Tc
 superconducting thin-film devices largely depends on the quality of
 trilayer superconductor-insulator-superconductor heterostructures. In
 high-Tc multilayer technology, the essential prerequisite is an all-
 epitaxial structure, smooth surface, and abrupt interface without
 interdiffusion. However, the difficulty of oxygen diffusion through
 insulators into bottom superconducting layers is a common problem. The
 authors note that Sr2AlTaO6 (SAT) is an excellent insulator with a good
 lattice match to YBCO and promising dielectric properties. The authors
 used PLD to deposit SAT/NdBa2Cu3O7-d (NBCO) bilayers on La-doped
 Sr2AlTaO6 (LSAT) and STO substrates, and they found that because of the
 high stability and crystallinity of the SAT insulator, oxygen diffusion
 through SAT into the bottom NBCO layer became difficult. They did find,
 however, that after annealing for 5 h, the Tc reached a nearly saturated
 value of 90.5 K. Measurements of the magnetization hysteresis loop
 yielded a critical current density of 2.8 x 10^6 A/cm^2 at 77 K in an
 applied magnetic field of 100 G, results comparable with those on single
 NBCO layers deposited on LSAT and STO substrates.
<p>
 Measurements of the c-axis conductance have been carried out by J. C.
 Martinez et al. (Mainz) on superlattices (total thickness ~~ 200 nm) in
 which the repeating layers were two unit cells of YBa2Cu3O7-d (Y-123)
 and seven unit cells of PrBa2Cu3O7-d (Pr-123). These quasi-2D
 structures did not show clear superconducting coupling along the c axis.
 Instead, the authors observed tunneling with a gap of Delta_c = 5.0+-0.5
 meV for the direction perpendicular to the superconducting planes. The
 conductance spectra showed well-defined quasi-periodic structures
 attributed to the superlattice structure. From the data, the authors
 deduced a low-temperature c-axis coherence length of xi_c = 0.24+-0.03
 nm.
<p>
<p>
 RBa2Cu3O7-d
<p>
 Measurements of the normal-state c-axis magnetoresistance have been used
 by N. E. Hussey (Tokyo) et al. to probe the origin of the metallic c-
 axis transport in slightly overdoped YBa2Cu3O7-d (d = 0.05). The
 authors find that an orbital contribution to the transverse
 magnetoresistance, a signature of coherent band motion, arises only from
 the component of the magnetic field perpendicular to the CuO chains.
 According to the authors, this result implies that the chains are
 primarily responsible for coherent c-axis transport in YBa2Cu3O7-d and
 that those regions of the CuO2 planes not hybridized with the chains
 remain effectively two-dimensional, even in the absence of a normal-
 state gap.
<p>
 A preprint by H. J. Fink (UC-Davis) reports a theoretical analysis of
 surface-resistance experiments by the Vancouver group on high-quality
 YBa2Cu3O6.99 single crystals. The resistance measurements are from 1.14
 to 75.3 GHz, and the author finds good numerical agreement over that
 frequency interval for all temperatures. The author extracted the real
 part of the microwave conductivity sigma'(T) and obtained a Drude-like
 conductivity spectrum below 25 K, in agreement with the model. The
 author also found that the scattering rate of the thermally excited
 quasiparticles increases with temperature, in agreement with a
 Grueneisen temperature-dependent intrinsic resistivity at low
 temperatures.
<p>
 Direct measurements of the forces on superconducting vortices in
 YBa2Cu3O7-d using high-Q single-crystal-silicon double-torsional
 oscillators have been carried out by J. T. Markert et al. (Texas-Austin)
 and by J. T. Markert and K. Mochizuki (Texas-Austin). In the first
 paper, the authors report studies of the crossover from pinning to
 viscous motion of vortices. In the second paper, the authors measured
 the longitudinal force but found no evidence for the transverse force
 within experimental error.
<p>
 High-resolution capacitance dilatometry studies from 5 K to 500 K of
 untwinned YBa2Cu3Ox (Y-123) single crystals with x ~~ 6.95 and 7.0 have
 been carried out by P. Nagel (Karlsruhe) et al. Large contributions to
 the thermal expansivities due to O ordering were found for x ~~ 6.95,
 but these disappear below a kinetic glass-like transition near room
 temperature. The kinetics at this transition are governed by an energy
 barrier of 0.98+-0.07 eV, in good agreement with other O-ordering
 studies. Using thermodynamic arguments, the authors show that O
 ordering in the Y-123 system is particularly sensitive to uniaxial
 stress along the chain axis, and they suggest that the lack of well-
 ordered chains in Nd-123 and La-123 is most likely a consequence of a
 chemical-pressure effect.
<p>
 The fabrication of YBa2Cu3O7-d (YBCO) superconductors using the top-
 seeded melt-growth (TSMG) process with a multiseeding technique is
 reported by Y. A. Lee (KAERI) et al. By using several seeds at the same
 time, large samples could be fabricated in a short time with a simple
 heat treatment. The best YBCO samples were obtained when the seeds were
 arranged with no spacing between them. The individual grains in the
 YBCO sample then behaved as a single domain and showed no deterioration
 of magnetic flux-trapping properties at the grain boundaries.
<p>
<p>
 Other Cuprates
<p>
 Using an ac technique, R. S. Gonnelli (Torino) et al. have measured the
 ab-plane resistivity of La2-xSrxCuO4 single crystals with small Sr
 content (0.052 <= x <= 0.075) between 4.2 K and 300 K. The authors
 interpret the deviation from linearity of the rho_[ab](T) curve at a
 temperature T_[ch] as due to a progressive slowing down of the
 fluctuations of preformed charge stripes. The authors also speculate
 that an electronic phase transition from a nematic stripe phase to a
 more ordered smectic phase is responsible for some anomalies near Tc.
<p>
 Andreev-reflection and tunneling studies of a single crystal of
 underdoped Nd1.85Ce0.15CuO4+d (NCCO) have been carried out by A.
 Mourachkine (Brussels) using Ag, Pt-Ir, and Nb tips to clarify the
 symmetry of the order parameter. The author observed a Josephson
 current using a Nb tip, suggesting the presence of an s-wave order
 parameter, and observed a zero-bias conductance peak using a Ag tip,
 suggesting the presence of a d-wave order parameter.
<p>
 Two preprints by L. Fabrega (Barcelona) et al. report on properties of
 Hg-based cuprate superconductors. In one of these, the authors
 performed muon-spin and magnetization experiments to investigate the
 effects of O and Re in Hg1-xRexBa2CuO4+d [(Hg,Re)-1201] superconductors.
 Near optimal doping, the authors found that the optimal Tc and lambda
 values were nearly independent of x. Moreover, no traces of c-axis
 metallization induced by Re were observed. In the second preprint, the
 authors report ac susceptibility studies of HgBa2CuO4+d (Hg-1201),
 Hg0.82Re0.18Ba2CaCu2O6+d [(Hg,Re)-1212], and Hg0.82Re0.18Ba2Ca2Cu3O8+d
 [(Hg,Re)-1223]. The authors found that chi"(T) in a dc field exhibits
 two peaks, and they attribute the peak at higher temperature to surface
 barriers and that at lower temperature to bulk pinning.
<p>
 Inelastic and elastic neutron scattering experiments have been carried
 out by U. Staub (PSI-Villigen) et al. to investigate the magnetic
 properties of Pr in Pb2Sr2PrCu3O8+d. The authors found a magnetic
 ordering of the Pr sublattice with two different ordering wave vectors,
 corresponding to antiferromagnetic order within the plane and
 ferromagnetic and antiferromagnetic ordering along the c direction,
 similar to the R = Tb analog. The authors also were able to find a set
 of crystal-field parameters describing the observed magnetic
 excitations, and they conclude that their results strongly suggest the
 importance of the magnetic quasi-triplet ground state to the suppression
 of superconductivity by Pr in these cuprates.
<p>
 The possibility of coexistence of superconductivity and ferromagnetism
 in the hybrid ruthenate-cuprate compound RuSr2GdCu2O8 (Ru-1212) has been
 investigated theoretically by H. Shimahara and S. Hata (Hiroshima). The
 authors calculated critical fields for superconductivity taking into
 account the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state in a model
 with Fermi surfaces whose shapes are similar to those obtained by a band
 calculation. They found that the FFLO critical field is enhanced by the
 Fermi-surface structure and that it is large enough to support
 coexistence of superconductivity and ferromagnetism on a microscopic
 scale in Ru-1212. The authors also suggest a scanning tunneling
 microscope experiment to probe the spatial oscillation of the order
 parameter.
<p>
<p>
 RNi2B2C
<p>
 The paramagnon contribution to the quasiparticle inelastic scattering
 rate in disordered superconductors has been calculated by T. P.
 Devereaux (Waterloo). Using Anderson's exact eigenstate formalism, the
 author found that the scattering rate is Stoner-enhanced and is further
 enhanced by the disorder relative to the clean case in a manner similar
 to the disorder enhancement of the long-range Coulomb contribution. The
 author discusses the results in connection with the possibility of
 conventional or unconventional superconductivity in the borocarbides.
<p>
 Precise measurements of the resistivity vs temperature of YNi2B2C (Tc =
 15.5 K) single crystals have been analyzed by R. S. Gonnelli (Torino) et
 al. in the framework of Bloch-Grueneisen theory and electron-phonon
 coupling. The authors determined the transport electron-phonon spectral
 function that best fits the resistivity data, inserted this into the
 real-axis Eliashberg equations, and then solved these equations to
 determine the normalized tunneling conductance under the assumptions of
 s-wave and d-wave symmetry.
<p>
 Ni K-edge extended x-ray absorption fine structure (EXAFS) measurements
 on superconducting YNi2B2C (Tc ~~ 15.2 K) in the temperature range 5-220
 K have been performed by A. Yu. Ignatov (Southern Illinois) et al. The
 results show that below T_p ~ 60 K local structure is distorted from
 the perfect I4/mmm crystalline structure expected from diffraction
 measurements. Two different Ni-Ni distances separated by ~0.09 Angstrom
 can be extracted at 5 K. The authors argue that YNi2B2C is
 inhomogeneous at the atomic length scale.
<p>
 Measurements by H. Michor et al. (Wien) have revealed that the reduction
 of Tc in solid solutions of Y1-xRxNi2B2C (R = rare earth) under
 hydrostatic pressure is significantly enhanced relative to the behavior
 of YNi2B2C. The authors show that this enhanced reduction is due to a
 pressure-induced increase of the magnetic exchange integral J_[sf]. The
 corresponding effect of chemical pressure arising from the change of the
 lattice parameter a upon rare-earth substitution is found to be in
 quantitative agreement with the hydrostatic pressure effect.
<p>
<p>
 Vortices
<p>
 A preprint by T. B. Doyle (Natal) et al. presents results of
 calculations for the field profiles as well as the local and global
 magnetization in Bi2Sr2CaCu2O8+d (Bi-2212) single-crystal specimens in
 the vortex-solid/liquid intermediate state. The calculated results are
 in good agreement with the results of local induction measurements. The
 calculations are based on the assumption of a first-order transition
 between different equilibrium constitutive B^[rev](H) relations for the
 solid and liquid vortex-matter states at a characteristic hysteretic
 internal field H_m. The authors describe procedures for the accurate
 determination of the entropy of melting from global and local
 magnetization data in the intermediate-state regime.
<p>
 A related paper by T. B. Doyle (Natal) et al. reports self-consistent
 fits of a treatment including specimen shape, vortex pinning, and
 surface effects to experimental Bi-2212 magnetization data for platelet
 and prism single-crystal specimen geometries. In accord with
 theoretical expectations, the platelet specimen exhibits a sharp
 dimensional crossover transition from 3D to quasi-2D (arrowhead)
 behavior at about the predicted crossover field B_[2D] for temperatures
 T <= 40 K. The magnetic hysteresis in this specimen is shown to be
 predominantly due to the shape/geometry effect and to 3D small-bundle
 and large-bundle collective pinning behavior above and below this
 transition, respectively. The prism specimen shows a diffuse crossover
 transition, and the hysteresis is shown to be dominated by surface
 vortex pinning and a distributed surface-barrier mechanism.
<p>
 A preprint by A. Morello (Grenoble and Torino) et al. reports
 measurements of the irreversible magnetization of an overdoped
 Bi2Sr2CuO6 (Bi-2201) single crystal up to B = 28 T and down to T = 60
 mK, from which the irreversibility line B_[irr](T) was determined. The
 authors found that the data can be interpreted in the entire temperature
 range as a 3D anisotropic vortex-lattice melting line with Lindemann
 number c_L = 0.13.
<p>
 Fine structure in the magnetization of small Al disks (kappa = lambda/xi
 ~~ 0.3) with diameters 1.5 micrometers and 2.4 micrometers in magnetic
 fields along the disk axis is reported by A. K. Geim (Nijmegen) et al.
 The authors compare their results with Ginzburg-Landau calculations and
 interpret the observed multiple phase transitions in terms of either
 merger of vortices into a single giant vortex or switching between
 different metastable arrays of the same number of vortices.
<p>
 Magnetization measurements by S. Chaudhary (Indore) et al. show a
 pronounced peak effect in samples of Mo0.825Re0.175 and Mo0.8Re0.2. The
 peak effect occurs close to the H_[c2](T) line. The authors stress that
 the magnetization results do not exhibit any of the anomalies reported
 in CeRu2 or NbSe2.
<p>
 A preprint by P. Benetatos and M. C. Marchetti (Syracuse) reports
 calculations in which nonlinear hydrodynamics is used to evaluate
 disorder-induced corrections to the vortex-liquid tilt modulus for
 finite screening length and arbitrary disorder geometry. The authors'
 explicit results for aligned columnar defects yield a criterion for
 locating the Bose-glass transition at all fields.
<p>
 The transport properties of Nb/CuMn multilayers with a regular array of
 electron-beam-produced antidots (holes) have been measured by C.
 Attanasio (Salerno) et al. at different temperatures in the presence of
 external perpendicular magnetic fields far above the matching field.
 Upon measuring the I-V characteristics, the authors observed hysteresis,
 which disappeared when approaching the upper critical magnetic field
 H_[c2](T). The authors relate the onset of the hysteresis to the
 presence of an irreversibility line.
<p>
<p>
 Theory
<p>
 As noted by N. A. Mortensen (Technical University of Denmark) et al.,
 the magnetic resonance at 41 meV observed in neutron-scattering studies
 of YBa2Cu3O7-d holds a key position in the understanding of high-Tc
 superconductivity. Starting with the SO(5) model for superconductivity
 and antiferromagnetism, the authors have calculated the effect of an
 applied magnetic field on the neutron-scattering cross section of the
 magnetic resonance. In the presence of vortices, the neutron-scattering
 cross section shows clear signatures of fluctuations in both the
 magnitude and phase of the superconducting order parameter psi. The
 authors find that in reciprocal space (a) the scattering amplitude is
 zero at (pi/a,pi/a), (b) the resonance peak is split into a ring with
 radius pi/d centered at (pi/a,pi/a), where d is the lattice constant of
 the triangular vortex lattice, and (c) the splitting pi/d therefore
 scales with the magnetic field as sqrt[B.
<p>
 A preprint by J.-X. Li (Nanjing) et al. uses the slave-boson approach to
 the t-t'-J model to examine the spectra observed in ARPES measurements
 and the resonance peak observed by neutron scattering. The authors find
 that the peak/dip/hump ARPES features arise from the scattering of
 electrons by collective spin excitations, which also give rise to the
 neutron resonance mode. The authors show that the theoretically
 expected doping dependencies and the dispersions of the peak/dip/hump
 positions are consistent with experiment. The results also indicate
 that the recently observed cos(6[theta]) deviation from the pure d-wave
 dependence of the gap parameter Delta(theta) also results from
 renormalization by spin fluctuations.
<p>
 Possible causes of deviations from the simple d_[x^2-y^2]-wave picture
 of high-Tc superconductivity observed in Bi-2212 have been analyzed by
 G.G.N. Angilella (Catania) et al. The authors considered the issue of
 whether nonlinear, high-energy corrections to the superconducting energy
 spectrum E_k around the gap nodes induce deviations in the predicted
 power-law behavior of several electronic properties at low or
 intermediate temperatures. The authors find that nonlinear corrections
 to E_k in general introduce additional energy scales into the problem,
 and that deviations from the usual power-law behavior of the
 superconducting electronic properties are expected at such energy
 scales. However, the authors find that both the magnitude and sign of
 the deviations depend upon the model under consideration.
<p>
 A microscopic model for strongly correlated electrons with both on-site
 and nearest-neighbor Coulomb repulsion on a 2D square lattice has been
 investigated by M. Berciu and S. John (Toronto). The authors used the
 configuration interaction (CI) method to study the quantum translational
 and rotational motion of various charge magnetic solitons and soliton
 pairs. The model provides a unified microscopic basis for (a) non-
 Fermi-liquid transport properties, (b) d-wave preformed charge carrier
 pairs, (c) mid-infrared optical absorption, (d) destruction of
 antiferromagnetic long-range order with doping, and (e) certain aspects
 of angle-resolved photoemission spectroscopy (ARPES).
<p>
 A related paper by M. Berciu and S. John (Toronto) demonstrates that the
 CI approximation captures essential features of the exact (Bethe Ansatz)
 solution of the 1D Hubbard model and that it systematically describes
 fluctuation and quantum-tunneling corrections to the Hartree-Fock
 approximation.
<p>
 Some of the consequences of the quantum-critical-point scenario are
 discussed in a preprint by C. Di Castro et al. (Roma). In particular,
 the authors show that the strong k-dependent scattering of the
 quasiparticles with quasi-critical charge and spin fluctuations
 reproduces the main features of the low-energy spectral weights and the
 observed Fermi surfaces. In the underdoped cuprates, the attractive k-
 dependent charge scattering drives the formation of the pseudogap at the
 M points below the crossover temperature T*.
<p>
 A class of nearly exactly solvable models of the electronic spectrum of
 two-dimensional systems with fluctuations of short-range order of
 dielectric (e.g., antiferromagnetic) or superconducting type is
 considered in a preprint by M. V. Sadovskii (Ekaterinburg). Such models
 lead to the formation of an anisotropic pseudogap state on certain parts
 of the Fermi surface. The models can be used to calculate the spectral
 density, density of states, and conductivity in the normal state, as
 well as some properties in the superconducting state.
<p>
 Andreev interferometry - the sensitivity of the tunneling current to
 spatial variation in the local superconducting order at an interface -
 is proposed in a preprint by D. E. Sheehy et al. (Illinois-Urbana) as a
 probe of the spatial structure of the phase correlations in the
 pseudogap state of the cuprate superconductors. To demonstrate this
 idea theoretically, the authors consider a simple tunneling model in
 which the tunneling current is related to the equilibrium phase-phase
 correlator in the pseudogap state. The authors suggest that
 measurements of the low-voltage conductance through mesoscopic contacts
 of varying areas should make it possible to obtain phase-phase
 correlation information.
<p>
 The Josephson current for c-axis coherent tunneling between two layered
 superconductors, each with internal coherent tight-binding intra- and
 interlayer quasiparticle dispersion, has been calculated exactly by G.
 B. Arnold (Notre Dame) and R. A. Klemm (Argonne). The results also
 apply when one or both of the superconductors is a bulk material, and
 they include the usually neglected effects of surface states. For weak
 tunneling, the results reduce to the authors' previous results derived
 using the tunneling Hamiltonian. The authors find that regardless of
 the order-parameter symmetry, these coherent-tunneling results using a
 tight-binding intralayer quasiparticle dispersion are inconsistent with
 recent c-axis twist bicrystal experiments by Q. Li et al. [Phys. Rev.
 Lett. 83, 4160 (1999)] in Bi-2212.
<p>
 The structure of the Meissner effect in a current-carrying cylindrical
 wire with arbitrary disorder has been studied by J. Sanchez-Canizares
 (Madrid) et al. using a numerical procedure that is exact within the
 quasiclassical approximation. The authors find a distribution of
 current that is nonmonotonic as a function of the radial coordinate.
 For high currents, the authors find that a robust gapless
 superconducting state develops at the surface of both clean and dirty
 wires.
<p>
 An exact analytical solution has been found by G. P. Mikitik (Kharkov)
 and E. H. Brandt (MPI-Stuttgart) for the critical-state problem in long,
 thin superconducting strips in a perpendicular magnetic field when the
 critical current density Jc(B) depends upon the local magnetic induction
 according to a certain three-parameter model. The authors assert that
 the model describes both isotropic superconductors with this Jc(B)
 dependence and superconductors with anisotropic pinning described by a
 dependence Jc(theta), where theta is the tilt angle of the flux lines
 away from the normal to the specimen plane.
<p>
 A related paper by G. P. Mikitik (Kharkov) and E. H. Brandt (MPI-
 Stuttgart) describes the solutions for the currents and fields in a
 thin, flat superconductor of arbitrary shape and with arbitrary in-plane
 and out-of-plane flux-pinning anisotropy, when the superconductor is
 subjected to an external magnetic field normal to its plane. The
 authors show that the general three-dimensional critical-state problem
 for this superconductor reduces to the two-dimensional problem of an
 infinitely thin sample of the same shape but with a modified induction
 dependence of the critical sheet current. Methods of solving the latter
 problem are well known. This finding enables the study of critical
 states in realistic samples of high-Tc superconductors with various
 types of anisotropic flux pinning. As examples, the authors investigate
 the critical states of long strips and rectangular platelets of high-Tc
 superconductors with pinning by either the ab planes or extended defects
 aligned with the c axis.
<p>
<p>
 Other Activities
<p>
 The electron-phonon coupling in fullerene C28 has been calculated from
 first principles by N. Breda (Milano) et al. The authors find that the
 value of the associated coupling constant lambda/N(0) is a factor of
 three larger than that for C60. Assuming, for C28-based solids, values
 of the Coulomb pseudopotential mu* and the density of levels at the
 Fermi surface N(0) similar to those in the alkali-doped fullerides
 A3C60, the authors predict Tc(C28) ~~ 8 Tc(C60).
<p>
 A preprint by M. Suenaga (Brookhaven) et al. reports that ac losses in
 stacks of powder-in-tube (PIT) processed Bi-2223/Ag tapes were measured
 in perpendicular magnetic fields and compared with calculated hysteresis
 losses based on the critical-state model. The authors found that the
 agreement between the calculated and measured losses is excellent for
 fields beyond the full penetration fields, but that the theory does not
 fully account for the low-field losses.
<p>
 A finite-element program has been used by B. Zeimetz et al. (Cambridge)
 to calculate current distributions in superconductors, assuming a
 nonlinear (power-law or percolation-type) local dependence of the
 electric field on current density. The authors studied a bicrystal
 geometry, which forms the basic building block of Bi-2223 PIT tapes and
 other polycrystalline conductors. The results support the propositions
 of the railway-switch model, insofar as grain boundaries do not play a
 dominant role in Bi-2223 PIT tapes. However, the brick-wall model also
 is vindicated, in that c-axis transport plays a decisive role for
 dissipation and critical currents. The crucial point is that the
 intrinsic Jc anisotropy of the material is more important than the
 details of the microstructural geometry.
<p>
 Five related preprints, by R. Weinstein (TCSUH) et al., R.-P. Sawh
 (TCSUH) et al., A. Gandini (TCSUH) et al., and two by W. Hennig et al.
 (TCSUH), discuss the achievement of strong pinning in trapped-field
 magnets and the application of such materials for magnetic levitation.
 The paper by R. Weinstein et al. discusses numerous aspects of U/n
 processing: (a) insertion of uranium into HTS precursor powders prior
 to texturing and (b) irradiation with thermal neutrons after texturing.
 One of the preprints by W. Hennig et al. reports some advantages of a
 levitation system in which a superconducting trapped-field magnet of 1.5
 T levitates above the center of a ring of zero-field-cooled high-
 temperature superconductors.
<p>
<p>
 Contributed by John R. Clem
<p>
 <hr>
<p>
 Contents: Preprints begin on page 6; Coming Events begin on page 11;
 and FYI is on page 13.
<p>
 High-Tc Update is available without charge to interested persons.
 Recipients are expected to participate in this information exchange by
 sending us preprints, reprints, meeting news, research news, etc.
 Contributions to defray the cost of newsletter processing and mailing
 are welcome.
<p>
 <hr>
<p>
 PREPRINTS
 To obtain a particular preprint, contact the first author at the address
 given at the end of the citation. Help us expand this list by sending
 us your complete preprint. Please specify where and when your paper was
 submitted. An * next to an entry indicates it is a correction or
 revision of a previous entry. PACS codes and/or key words are given at
 the end of the citation.
<p>
<p>
 Giuseppe G. N. Angilella, Asle Sudbo, and Renato Pucci, "Extended
 d_[x^2-y^2]-Wave Superconductivity: Flat Notes in the Gap and the Low-
 Temperature Asymptotic Properties of High-Tc Superconductors." To be
 published in Eur. Phys. J. B. Dipartimento di Fisica, Universita degli
 Studi di Catania, 57 Corso Italia, I-95129 Catania, ITALY; telephone +39
 095 7195 499; telefax +39 095 383023; e-mail
 <a href="mailto:giuseppe.angilella@ct.infn.it">giuseppe.angilella@ct.infn.it;</a> preprint also available at
 <a href="http://xxx.lanl.gov/abs/cond-mat/0001046">http://xxx.lanl.gov/abs/cond-mat/0001046.</a> 74.25.-q; 74.25.Jb; 74.20.Mn;
 74.72.Hs.
<p>
 G. B. Arnold and R. A. Klemm, "Theory of Coherent c-Axis Josephson
 Tunneling Between Layered Superconductors." Submitted to Phys. Rev. B.
 Department of Physics, University of Notre Dame, Notre Dame, IN 46556;
 R. A. Klemm's e-mail at Argonne National Laboratory <a href="mailto:klemm@anl.gov">klemm@anl.gov;</a>
 preprint also available at <a href="http://xxx.lanl.gov/abs/cond-mat/0001272">http://xxx.lanl.gov/abs/cond-mat/0001272.</a>
<p>
 C. Attanasio, T. Di Luccio, L. V. Mercaldo, S. L. Prischepa, R. Russo,
 M. Salvato, L. Maritato, S. Barbanera, and A. Tuissi, "Irreversibility
 Line in Nb/CuMn Multilayers with a Regular Array of Antidots."
 Submitted to Phys. Rev. B. Dipartimento di Fisica and INFM, Universita
 degli Studi di Salerno, I-84081 Baronissi (Salerno), ITALY; L. V.
 Mercaldo's e-mail <a href="mailto:luciam@physics.unisa.it">luciam@physics.unisa.it;</a> preprint also available at
 <a href="http://xxx.lanl.gov/abs/cond-mat/0001205">http://xxx.lanl.gov/abs/cond-mat/0001205.</a> 74.60.Ge; 74.60.Jg.
<p>
 Panayotis Benetatos and M. Cristina Marchetti, "A Hydrodynamic Approach
 to the Bose-Glass Transition." Presented at the First Euroconf. on
 Vortex Matter in Superconductors (VORTEX99), Crete, Greece, Sept. 18-24,
 1999. Department of Physics, Syracuse University, Syracuse, NY 13244;
 M. Cristina Marchetti's e-mail <a href="mailto:mcm@suhep.phy.syr.edu">mcm@suhep.phy.syr.edu;</a> preprint also
 available at <a href="http://xxx.lanl.gov/abs/cond-mat/0001034">http://xxx.lanl.gov/abs/cond-mat/0001034.</a> Key words:
 vortex matter, hydrodynamics, Bose glass, tilt modulus.
<p>
 Mona Berciu and Sajeev John, "A Microscopic Model for d-Wave Charge
 Carrier Pairing and Non-Fermi-Liquid Behavior in a Purely Repulsive 2D
 Electron System." Submitted to Phys. Rev. B. Department of Physics,
 University of Toronto, 60 St. George Street, Toronto, Ontario, CANADA
 M5S 1A7; e-mail <a href="mailto:berciu@physics.utoronto.ca">berciu@physics.utoronto.ca;</a> Web sites
 www.physics.utoronto.ca/~berciu or www.physics.utoronto.ca/~john;
 preprint also available at <a href="http://xxx.lanl.gov/abs/cond-mat/0001235">http://xxx.lanl.gov/abs/cond-mat/0001235.</a>
<p>
 Mona Berciu and Sajeev John, "Quantum Dynamics of Charged and Neutral
 Magnetic Solitons: Spin-Charge Separation in the One-Dimensional
 Hubbard Model." Submitted to Phys. Rev. B. Department of Physics,
 University of Toronto, 60 St. George Street, Toronto, Ontario, CANADA
 M5S 1A7; e-mail <a href="mailto:berciu@physics.utoronto.ca">berciu@physics.utoronto.ca;</a> Web sites
 www.physics.utoronto.ca/~berciu or www.physics.utoronto.ca/~john;
 preprint also available at <a href="http://xxx.lanl.gov/abs/cond-mat/9912460">http://xxx.lanl.gov/abs/cond-mat/9912460.</a>
 71.27.+a; 71.10.Fd; 74.20.Mn.
<p>
 N. Breda, R. A. Broglia, G. Colo, G. Onida, D. Provasi, and E. Vigezzi,
 "Room Temperature Organic Superconductor?" Dipartimento di Fisica,
 Universita di Milano, Via Celoria 16, I-20133 Milano, ITALY; G. Colo's
 e-mail at INFM <a href="mailto:gianluca.colo@mi.infn.it">gianluca.colo@mi.infn.it;</a> preprint also available at
 <a href="http://xxx.lanl.gov/abs/cond-mat/0001133">http://xxx.lanl.gov/abs/cond-mat/0001133.</a> 74.70.Wz; 63.20.Kr; 61.48.+c.
<p>
 C. Castellani, C. Di Castro, M. Grilli, and A. Perali, "Stripe Ordering
 and Two-Gap Model for Underdoped Cuprates." Submitted to the Proc. of
 the 6th Int. Conf. on Mater. and Mech. of Supercond. and High Temp.
 Supercond. (M^2S-HTSC-VI), Houston, Tex., Feb. 20-25, 2000.
 Dipartimento di Fisica, Universita di Roma "La Sapienza," Piazzale Aldo
 Moro 2, I-00185 Rome, ITALY; A. Perali's e-mail at INFM
 <a href="mailto:andrea.perali@roma1.infn.it">andrea.perali@roma1.infn.it;</a> preprint also available at
 <a href="http://xxx.lanl.gov/abs/cond-mat/0001231">http://xxx.lanl.gov/abs/cond-mat/0001231.</a>
<p>
 Biplab Chattopadhyay, B. Bandyopadhyay, Asok Poddar, P. Mandal, A. N.
 Das, and B. Ghosh, "Impurity Substitution in Bismuth and Thallium
 Cuprates: Suppression of Tc and Estimation of Pseudogap." To be
 published in Physica C (in press). Saha Institute of Nuclear Physics,
 1/AF Bidhannagar, Calcutta 700 064, INDIA; telefax +91 33 3374637; e-
 mail <a href="mailto:biplab@cmp.saha.ernet.in">biplab@cmp.saha.ernet.in.</a> Key words: high-Tc cuprate
 superconductors, Tc suppression by impurities, pair-breaking formalism,
 pseudogap. 74.72.-h; 74.72.Hs; 74.72.Fq; 74.25.Fy.
<p>
 Sujeet Chaudhary, S. B. Roy, P. Chaddah, P. K. Babu, R. Nagarajan, and
 L. C. Gupta, "Peak Effect in the Superconducting Mixed State of Bulk Mo-
 Re Alloys: A dc Magnetization Study." To be published in Phil. Mag. B.
 Low Temperature Physics Laboratory, Centre for Advanced Technology,
 Indore 452 013, INDIA; e-mail <a href="mailto:sujeetc@cat.ernet.in">sujeetc@cat.ernet.in.</a>
<p>
 T. P. Devereaux, "Quasiparticle Inelastic Lifetime from Paramagnons in
 Disordered Superconductors." Department of Physics, University of
 Waterloo, Waterloo, Ontario, CANADA N2L 3G1; e-mail
 <a href="mailto:tpd@gandalf.uwaterloo.ca">tpd@gandalf.uwaterloo.ca;</a> preprint also available at
 <a href="http://xxx.lanl.gov/abs/cond-mat/0001352">http://xxx.lanl.gov/abs/cond-mat/0001352.</a> 74.70.Ad; 74.20.-z; 74.20.Mn;
 74.40.+k.
<p>
 C. Di Castro, L. Benfatto, S. Caprara, C. Castellani, and M. Grilli,
 "The Physics of the Stripe Quantum Critical Point in the Superconducting
 Cuprates." INFM and Dipartimento di Fisica, Universita di Roma "La
 Sapienza," I-00185 Rome, ITALY; preprint also available at
 <a href="http://xxx.lanl.gov/abs/cond-mat/0001229">http://xxx.lanl.gov/abs/cond-mat/0001229.</a>
<p>
 T. B. Doyle, R. Labusch, and R. A. Doyle, "A Self-Consistent Study of
 Vortex Pinning/Dynamics in Single Crystal BSCCO-2212 Platelet and Prism
 Specimen Geometry." To be published in Physica C. Department of
 Physics, University of Natal, King George V Avenue, Durban 4041, SOUTH
 AFRICA; telephone +27 31 260 2775; telefax +27 31 261 6550. 74.60.Ge;
 74.60.Jg.
<p>
 T. B. Doyle, R. Labusch, and R. A. Doyle, "The Solid/Liquid Intermediate
 State in BSCCO Single Crystals." To be published in Physica C.
 Department of Physics, University of Natal, King George V Avenue, Durban
 4041, SOUTH AFRICA; telephone +27 31 260 2775; telefax +27 31 261 6550.
 74.60.Ge; 74.60.Jg.
<p>
 V. Dzhunushaliev, "A String Approximation for the Cooper Pair in High-Tc
 Superconductivity." Institute fuer Mathematik, Universitaet Potsdam, Am
 Neuen Palais 10, 14469 Potsdam, GERMANY; e-mail <a href="mailto:dzhun@rz.uni-potsdam.de">dzhun@rz.uni-potsdam.de;</a>
 preprint also available at <a href="http://xxx.lanl.gov/abs/cond-mat/0001257">http://xxx.lanl.gov/abs/cond-mat/0001257.</a>
 74.20.Mn; 12.38.Lg.
<p>
 L. Fabrega, J. Fontcuberta, A. Serquis, and A. Caneiro, "Distinguishable
 Effects of Oxygen and Re in Hg-1201 Superconductors." Submitted to
 Phys. Rev. B. Institut de Ciencia de Materials de Barcelona, C.S.I.C.,
 Campus de la Universitat Autonoma de Barcelona, E-08193 Bellaterra,
 SPAIN; telephone +34 93 580 1853; telefax +34 93 580 5729; e-mail
 <a href="mailto:lourdes@icmab.es">lourdes@icmab.es.</a> 74.72.Gr; 76.75.+i; 74.62.Dh.
<p>
 L. Fabrega, A. Sin, A. Calleja, and J. Fontcuberta, "ac Response of Hg-
 Based Superconductors: Surface Barrier and Bulk Pinning Contributions."
 To be published in Phys. Rev. B. Institut de Ciencia de Materials de
 Barcelona, C.S.I.C., Campus de la Universitat Autonoma de Barcelona, E-
 08193 Bellaterra, SPAIN; telephone +34 93 580 1853; telefax +34 93 580
 5729; e-mail <a href="mailto:lourdes@icmab.es">lourdes@icmab.es.</a> 74.72.Gr; 74.25.Ha; 74.60.Ge.
<p>
 Herman J. Fink, "Microwave Surface Impedance of YBa2Cu3O6.99:
 Comparison of Theory and Experiment." To be published in Phys. Rev. B.
 Department of Electrical and Computer Engineering, University of
 California, Davis, CA 95616. 74.25.Nf; 74.72.-h; 74.20.De; 74.25.Fy;
 74.72.Bk.
<p>
 Andreas Franz, Andreas Wallraff, and Alexey V. Ustinov, "Measurements of
 Critical Current Diffraction Patterns in Annular Josephson Junctions."
 Physikalisches Institut III, Universitaet Erlangen-Nuernberg, D-91058
 Erlangen, GERMANY; Andreas Wallraff's e-mail <a href="mailto:wallraff@pkax01.physik.uni-">wallraff@pkax01.physik.uni-</a>
 erlangen.de; preprint also available at <a href="http://xxx.lanl.gov/abs/cond-">http://xxx.lanl.gov/abs/cond-</a>
 mat/9912302. 74.50.+r; 05.45.Yv; 85.25.Cp.
<p>
 A. Gandini, R. Weinstein, Y. R. Ren, R. P. Sawh, D. Parks, Y.C. Guo, B.
 Zeimetz, S. X. Dou, S. Toenies, C. Klein, and H. W. Weber, "Critical
 Current Enhancement in (Bi,Pb)2Sr2Ca2Cu3O10 Tapes Via Isotropic Quasi-
 Columnar Defects, Induced by Uranium Fission Products." Submitted to
 the Proc. of the 6th Int. Conf. on Mater. and Mech. of Supercond. and
 High Temp. Supercond. (M^2S-HTSC-VI), Houston, Tex., Feb. 20-25, 2000;
 to be published in Physica C. Contact Beam Particle Dynamics Group,
 University of Houston, 632 Science Research Bldg., Houston, TX 77204-
 5506; telephone (713) 743-3600; telefax (713) 747-4526.
<p>
 J. Gao, G. J. Lian, and G. C. Xiong, "Improved Initial Epitaxial Growth
 of Superconducting YBa2Cu3O7 Thin Films on Y-ZrO2 Substrates with a
 La1.85Sr0.15CuO4 Buffer Layer." To be published in Physica C (in
 press). Department of Physics, University of Hong Kong, Pokfulam Road,
 Hong Kong, PEOPLE'S REPUBLIC OF CHINA; telephone +852 2859 7948; telefax
 +852 2559 9152; e-mail <a href="mailto:jugao@hku.hk">jugao@hku.hk.</a> Key words: electrical
 resistivity, superconductivity, thin films.
<p>
 A. K. Geim, S. V. Dubonos, and J. J. Palacios, "Fine Structure in
 Magnetization of Individual Fluxoid States." University of Nijmegen,
 Toernooiveld 1, 6525 ED Nijmegen, THE NETHERLANDS; e-mail
 <a href="mailto:geim@sci.kun.nl">geim@sci.kun.nl;</a> preprint also available at
 <a href="http://xxx.lanl.gov/abs/cond-mat/0001129">http://xxx.lanl.gov/abs/cond-mat/0001129.</a> 74.76.-w.
<p>
 R. S. Gonnelli, V. A. Stepanov, A. Morello, G. A. Ummarino, D. Daghero,
 F. Licci, and G. Ubertalli, "ab-Plane Resistivity and Possible Charge
 Stripe Ordering in Strongly Underdoped La2-xSrxCuO4 Single Crystals."
 To be presented at the 6th Int. Conf. on Mater. and Mech. of Supercond.
 and High Temp. Supercond. (M^2S-HTSC-VI), Houston, Tex., Feb. 20-25,
 2000. INFM-Dipartimento di Fisica, Politecnico di Torino, Corso Duca
 degli Abruzzi 24, I-10129 Torino, ITALY; e-mail <a href="mailto:gonnelli@polito.it">gonnelli@polito.it;</a>
 preprint also available at <a href="http://xxx.lanl.gov/abs/cond-mat/9912434">http://xxx.lanl.gov/abs/cond-mat/9912434.</a>
<p>
 R. S. Gonnelli, V. A. Stepanov, A. Morello, G. A. Ummarino, G. Behr, G.
 Graw, S. V. Shulga, and S.-L. Drechsler, "Resistivity and Electron-
 Phonon Coupling in YNi2B2C Single Crystals." To be presented at the 6th
 Int. Conf. on Mater. and Mech. of Supercond. and High Temp. Supercond.
 (M^2S-HTSC-VI), Houston, Tex., Feb. 20-25, 2000. INFM-Dipartimento di
 Fisica, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129
 Torino, ITALY; e-mail <a href="mailto:gonnelli@polito.it">gonnelli@polito.it;</a> preprint also available at
 <a href="http://xxx.lanl.gov/abs/cond-mat/9912435">http://xxx.lanl.gov/abs/cond-mat/9912435.</a>
<p>
 W. Hennig, D. Parks, R.-P. Sawh, and R. Weinstein, "Enhanced Levitation
 Force Using YBa2Cu3Oy Trapped Field Magnets." Submitted to the Proc. of
 the 6th Int. Conf. on Mater. and Mech. of Supercond. and High Temp.
 Supercond. (M^2S-HTSC-VI), Houston, Tex., Feb. 20-25, 2000; to be
 published in Physica C. Contact Beam Particle Dynamics Group,
 University of Houston, 632 Science Research Bldg., Houston, TX 77204-
 5506; telephone (713) 743-3600; telefax (713) 747-4526.
<p>
 W. Hennig, D. Parks, R. Weinstein, R.-P. Sawh, and Y. Ren, "Stable
 Magnetic Levitation with Adjustable Ratio of Levitation Force to
 Restoring Force Using Rings of Zero Field Cooled YBa2Cu3Oy Samples."
 Submitted to Appl. Phys. Lett. Contact Beam Particle Dynamics Group,
 University of Houston, 632 Science Research Bldg., Houston, TX 77204-
 5506; telephone (713) 743-3600; telefax (713) 747-4526. 85.25.Am;
 74.80.Bj.
<p>
 J. M. Huijbregtse, B. Dam, R.C.F. Van der Geest, J. H. Rector, F. C.
 Klaassen, R. Elberse, and R. Griessen, "Natural Strong Pinning Sites in
 Laser Ablated YBa2Cu3O7-d Thin Films." Submitted to Phys. Rev. B.
 Contact B. Dam, Department of Physics and Astronomy, Faculty of
 Sciences, Vrije Universiteit, De Boelelaan 1081, NL-1081 HV Amsterdam,
 THE NETHERLANDS; e-mail <a href="mailto:dam@nat.vu.nl">dam@nat.vu.nl.</a> 61.72.Ff; 68.55.Ln; 74.60.Ge;
 81.15.-z.
<p>
 N. E. Hussey, H. Takagi, Y. Iye, S. Tajima, A. I. Rykov, and K. Yoshida,
 "Charge Confinement on the CuO2 Planes in Slightly Overdoped YBa2Cu3O7-d
 and the Role of Metallic Chains." To be published in Phys. Rev. B.
 Department of Physics, Loughborough University, Loughborough
 Leicestershire LE11 3TU, UNITED KINGDOM; telephone +44 1509 223347;
 telefax +44 1509 223986; e-mail <a href="mailto:n.e.hussey@lboro.ac.uk">n.e.hussey@lboro.ac.uk.</a> 74.25.Fy;
 74.70.Kn; 74.72.Bk.
<p>
 A. Yu. Ignatov, N. Ali, P. V. Konarev, M. Tischer, A. V. Tsvyashchenko,
 and L. N, Fomicheva, "Local Structure of YNi2B2C Superconductor
 Determined by X-Ray-Absorption Spectroscopy." To be published in Phys.
 Rev. B. Department of Physics, Southern Illinois University,
 Carbondale, IL 62901-4401; e-mail <a href="mailto:ignatov@physics.siu.edu">ignatov@physics.siu.edu.</a> 74.70.Dd;
 78.70.Dm.
<p>
 Young A. Jee, Chang-Joong Kim, Tae-Hyun Sung, and Gye-Won Hong, "Top-
 Seeded Melt Growth of Y-Ba-Cu-O Superconductor with Multiseeding." To
 be published in Supercond. Sci. & Technol. Contact Chang-Joong Kim,
 Superconductivity Research Laboratory, Korea Atomic Energy Research
 Institute, P.O. Box 105, Yusung, Taejon 305-600, SOUTH KOREA; telephone
 +82 42 868 8908; telefax +82 42 862 5496; e-mail
 <a href="mailto:cjkim2@nanum.kaeri.re.kr">cjkim2@nanum.kaeri.re.kr.</a> Key words: multiseeding, TSMG (Top-Seeded
 Melt Growth), Y-Ba-Cu-O, superconductor.
<p>
 D. Y. Jeong, H. K. Kim, Y. C. Kim, B. J. Kim, H. S. Lee, T. Tsuruta, Y.
 Matsui, and S. Horiuchi, "Microstructures in Tl-1223/Ag Tapes with
 Different Chemical Compositions and Jc's." To be published in Physica C
 (in press). Korea Electrotechnology Research Institute, Changwon 641-
 120, SOUTH KOREA; telephone +82 551 280 1671; telefax +82 551 280 1696;
 e-mail <a href="mailto:dyjeong@keri.re.kr">dyjeong@keri.re.kr.</a> Key words: Tl-1223, Ag, Jc .
<p>
 G. Krabbes, G. Fuchs, P. Schaetzle, S. Gruss, J. W. Park, F.
 Hardinghaus, G. Stoever, R. Hayn, S.-L. Drechsler, and T. Fahr, "Zn
 Doping of YBa2Cu3O7 in Melt Textured Materials: Peak Effect and High
 Trapped Fields." To be published in Physica C (in press). Institut
 fuer Festkoerper- und Werkstofforschung Dresden, Postfach 270016, D-
 01171 Dresden, GERMANY; telephone +49 351 4659 410; telefax +49 351 4659
 480; e-mail <a href="mailto:g.krabbes@ifw-dresden.de">g.krabbes@ifw-dresden.de.</a> Key words: peak effect,
 magnetization, pinning force, substitution effects, bulk
 superconductors.
<p>
 Jian-Xin Li, Chung-Yu Mou, and T. K. Lee, "A Consistent Picture for
 Resonance Neutron Peak and ARPES Spectra in High-Tc Superconductors."
 National Laboratory of Solid State Microstructures and Department of
 Physics, Nanjing University, Nanjing 210093, PEOPLE'S REPUBLIC OF CHINA;
 Chung-Yu Mou's telephone at National Tsing Hua University +886 3 574
 2537; telefax +886 3 572 3052; e-mail <a href="mailto:mou@phys.nthu.edu.tw">mou@phys.nthu.edu.tw;</a> preprint
 also available at <a href="http://xxx.lanl.gov/abs/cond-mat/9912488">http://xxx.lanl.gov/abs/cond-mat/9912488.</a> 71.10.-w;
 74.25.Jb; 74.25.Ha.
<p>
 Yijie Li, J. G. Wen, and K. Tanabe, "Effect of Post-Annealing Treatment
 on Superconducting Properties of Sr2AlTaO6/NdBa2Cu3O7-d Multilayers."
 To be published in Physica C. Superconductivity Research Laboratory,
 International Superconductivity Technology Center (ISTEC), 10-13
 Shinonome 1-chome, Koto-ku, Tokyo 135-0062, JAPAN; telephone +81 3 3536
 5709; telefax +81 3 3536 5717; e-mail <a href="mailto:yjli@istec.or.jp">yjli@istec.or.jp.</a> Key words:
 multilayers, thin films. 81.40.Ef; 73.61.-r; 68.55.Jk; 74.80.Dm.
<p>
 J. T. Markert and K. Mochizuki, "Smallness of the Transverse Force on
 Moving Vortices in YBa2Cu3O7-d." Submitted to Physica C: Proc. of the
 6th Int. Conf. on Mater. and Mech. of Supercond. and High Temp.
 Supercond. (M^2S-HTSC-VI), Houston, Tex., Feb. 20-25, 2000. Department
 of Physics, University of Texas, Austin, TX 78712-1081; telephone (512)
 471-1153; e-mail <a href="mailto:markert@physics.utexas.edu">markert@physics.utexas.edu.</a>
<p>
 John T. Markert, Koki Mochizuki, and Elizabeth E. Judge, "Direct
 Measurement of Forces on Superconducting Vortices Using High-Q Single-
 Crystal-Silicon Double-Torsional Oscillators." To be published in
 Physica B: Proc. of the 22nd Int. Conf. on Low Temp. Phys. (LT22),
 Helsinki, Finland, Aug. 5-11, 1999. Department of Physics, University
 of Texas, Austin, TX 78712-1081; telephone (512) 471-1153; e-mail
 <a href="mailto:markert@physics.utexas.edu">markert@physics.utexas.edu.</a> Key words: high-Q oscillators, vortices,
 pinning, friction.
<p>
 J. C. Martinez, A. Schattke, M. Jourdan, G. Jakob, and H. Adrian, "c-
 Axis Tunneling in YBa2Cu3O7-d/PrBa2Cu3O7-d Superlattices." To be
 published in Phys. Rev. B. Institut fuer Physik, Johannes Gutenberg-
 Universitaet Mainz, Staudingerweg 7, D-55099 Mainz, GERMANY; telephone
 +49 6131 39 23635; telefax +49 6131 39 25156; e-mail <a href="mailto:martinez@mail.uni-">martinez@mail.uni-</a>
 mainz.de. 74.80.Dm; 73.61.-r; 73.20.Dx.
<p>
 A. Matsushita, S. Horii, and Y. Yamada, "Effects of Pressure on the
 Electrical Resistivity of Pr1Ba2(Cu1-xMx)4O8 with M = Zn, Ni and x = 0,
 0.01, 0.02." To be published in Physica C (in press). National
 Research Institute for Metals, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047,
 JAPAN; telephone +81 298 59 2729; telefax +81 298 59 2701; e-mail
 <a href="mailto:akiyuki@nrim.go.jp">akiyuki@nrim.go.jp.</a> Key words: electrical resistivity, pressure
 effects, substitution effects. 74.62.Dh; 74.62.Fj.
<p>
 H. Michor, M. El-Hagary, L. Naber, E. Bauer, and G. Hilscher, "The
 Effect of Hydrostatic and Chemical Pressure upon the Exchange
 Interaction in Magnetic Borocarbide Superconductors." To be published
 in Phys. Rev. B. Institut fuer Experimentalphysik, Technische
 Universitaet Wien, Wiedner Hauptstrasse 8-10, A-1040 Wien, AUSTRIA;
 telephone +43 1 58801 13140; telefax +43 1 58801 13199; e-mail
 <a href="mailto:herwig@xphys.tuwien.ac.at">herwig@xphys.tuwien.ac.at.</a>
<p>
 Grigorii P. Mikitik and Ernst Helmut Brandt, "Critical State in Thin
 Anisotropic Superconductors of Arbitrary Shape." Submitted to Phys.
 Rev. B. Contact Ernst Helmut Brandt, Max Planck Institut fuer
 Metallforschung, D-70506 Stuttgart, GERMANY; e-mail <a href="mailto:ehb@physix.mpi-">ehb@physix.mpi-</a>
 stuttgart.mpg.de. 74.60.-w; 74.60.Ge; 74.60.Jg.
<p>
 Grigorii P. Mikitik and Ernst Helmut Brandt, "Exact Solution for the
 Critical State in Thin Superconductor Strips with Field Dependent or
 Anisotropic Pinning." Submitted to Phys. Rev. B. Contact Ernst Helmut
 Brandt, Max Planck Institut fuer Metallforschung, D-70506 Stuttgart,
 GERMANY; e-mail <a href="mailto:ehb@physix.mpi-stuttgart.mpg.de">ehb@physix.mpi-stuttgart.mpg.de.</a> 74.60.-w; 74.60.Ge;
 74.60.Jg.
<p>
 A. Morello, A.G.M. Jansen, R. S. Gonnelli, and S. I. Vedeneev, "3D-
 Melting Features of the Irreversibility Line in Overdoped Bi2Sr2CuO6 at
 Ultra-Low Temperature and High Magnetic Field." To be presented at the
 6th Int. Conf. on Mater. and Mech. of Supercond. and High Temp.
 Supercond. (M^2S-HTSC-VI), Houston, Tex., Feb. 20-25, 2000. Kamerlingh
 Onnes Laboratory, Leiden University, P.O. Box 9504, NL 2300 RA Leiden,
 THE NETHERLANDS; R. S. Gonnelli's e-mail at INFM, Torino, Italy
 <a href="mailto:gonnelli@polito.it">gonnelli@polito.it;</a> preprint also available at
 <a href="http://xxx.lanl.gov/abs/cond-mat/9912436">http://xxx.lanl.gov/abs/cond-mat/9912436.</a>
<p>
 Niels Asger Mortensen, H. M. Ronnow, Henrik Bruus, and Per Hedegard,
 "The Magnetic Neutron Scattering Resonance of High-Tc Superconductors in
 External Magnetic Fields: An SO(5) Study." Mikroelektronik Centret,
 Orsteds Plads, Bldg. 345 East, Technical University of Denmark, DK-2800
 Kgs. Lyngby, DENMARK; telephone +45 4525 5782; e-mail <a href="mailto:nam@mic.dtu.dk">nam@mic.dtu.dk;</a>
 preprint also available at <a href="http://xxx.lanl.gov/abs/cond-mat/0001338">http://xxx.lanl.gov/abs/cond-mat/0001338.</a>
 74.20.De; 74.25.Ha; 74.72.Bk; 78.70.Nx.
<p>
 A. Mourachkine, "Andreev Reflections and Tunneling Spectroscopy on
 Underdoped Nd1.85Ce0.15CuO4+d." Service de Physique des Solides,
 Universite Libre de Bruxelles, CP233, Boulevard du Triomphe, B-1050
 Brussels, BELGIUM; telephone +32 2 650 5751; telefax +32 2 650 5916; e-
 mail <a href="mailto:anmourac@ulb.ac.be">anmourac@ulb.ac.be.</a>
<p>
 A. Mourachkine, "CDW Ordering in Stripe Phase of Underdoped Cuprates."
 Service de Physique des Solides, Universite Libre de Bruxelles, CP233,
 Boulevard du Triomphe, B-1050 Brussels, BELGIUM; telephone +32 2 650
 5751; telefax +32 2 650 5916; e-mail <a href="mailto:anmourac@ulb.ac.be">anmourac@ulb.ac.be;</a> preprint also
 available at <a href="http://xxx.lanl.gov/abs/cond-mat/9912408">http://xxx.lanl.gov/abs/cond-mat/9912408.</a> Key words:
 superconductors, 2D cuprate SCs, 1D organic conductors, electrical
 properties.
<p>
 Peter Nagel, Volker Pasler, Christoph Meingast, Alexandre I. Rykov, and
 Setsuko Tajima, "Anomalously Large Oxygen-Ordering Contribution to the
 Thermal Expansion of Untwinned YBa2Cu3O6.95 Single Crystals: A Glass-
 Like Transition Near Room Temperature." Submitted to Phys. Rev. Lett.
 Forschungszentrum Karlsruhe, Institut fuer Nukleare Festkoerperphysik,
 P.O. Box 3640, D-76021 Karlsruhe, GERMANY; telephone +49 7247 82 4719;
 telefax +49 7247 82 4624; e-mail <a href="mailto:nagel@infp.fzk.de">nagel@infp.fzk.de;</a> preprint also
 available at <a href="http://xxx.lanl.gov/abs/cond-mat/0001287">http://xxx.lanl.gov/abs/cond-mat/0001287.</a> 74.72.Bk;
 64.70.Pf; 74.62.Fj; 65.50.+m.
<p>
 Akira Ono and Akio Watanabe, "Phase Transition and Superconductivity of
 (Ba,Sr,La)2YCu3Oz (z > 6.9)." To be published in Physica C (in press).
 National Institute for Research in Inorganic Materials, 1-1 Namiki,
 Tsukuba 305-0044, JAPAN; telephone +81 298 51 3354; telefax +81 298 52
 7449; e-mail <a href="mailto:ono@nirim.go.jp">ono@nirim.go.jp.</a> Key words: 1212-type cuprate, ionic
 radius, oxygen content, phase transition.
<p>
 M. V. Sadovskii, "Models of the Pseudogap State in Cuprates." To be
 presented at the 6th Int. Conf. on Mater. and Mech. of Supercond. and
 High Temp. Supercond. (M^2S-HTSC-VI), Houston, Tex., Feb. 20-25, 2000.
 Institute for Electrophysics, Russian Academy of Sciences, Ural Branch,
 620049 Ekaterinburg, RUSSIA; e-mail <a href="mailto:sadovski@ief.uran.ru">sadovski@ief.uran.ru;</a> preprint also
 available at <a href="http://xxx.lanl.gov/abs/cond-mat/9912318">http://xxx.lanl.gov/abs/cond-mat/9912318.</a>
<p>
 J. Sanchez-Canizares, J. Ferrer, and F. Sols, "Non-Linear and Non-Local
 Meissner Effect in Superconducting Wires." Departamento de Fisica
 Teorica de la Materia Condensada and Instituto de Ciencia de Materiales
 "Nicolas Cabrera," Universidad Autonoma de Madrid, E-28049 Madrid,
 SPAIN; e-mail <a href="mailto:ferrer@condmat01.geol.uniovi.es">ferrer@condmat01.geol.uniovi.es;</a> preprint also available
 at <a href="http://xxx.lanl.gov/abs/cond-mat/0001113">http://xxx.lanl.gov/abs/cond-mat/0001113.</a> 74.60.Jg; 74.55.+h;
 73.23.-b.
<p>
 H. Sato, A. Tsukada, M. Naito, and A. Matsuda, "La-214 Thin Films Under
 Epitaxial Strain." To be published in the Proc. of the 6th Int. Conf.
 on Mater. and Mech. of Supercond. and High Temp. Supercond. (M^2S-HTSC-
 VI), Houston, Tex., Feb. 20-25, 2000. NTT Basic Research Laboratories,
 3-1 Morinosato-Wakamiya, Atsugi-shi, Kanagawa 243-0198, JAPAN; telephone
 +81 46 240 3532; telefax +81 46 240 4717; e-mail
 <a href="mailto:hisashi@will.brl.ntt.co.jp">hisashi@will.brl.ntt.co.jp.</a>
<p>
 Mutsumi Sato, Gustavo A. Alvarez, Furen Wang, Tadashi Utagawa, Keiichi
 Tanabe, and Tadataka Morishita, "Preparation and Characterization of a-
 Axis Oriented NdBa2Cu3O7-d/PrBa2(Cu,Co)3O7-d/NdBa2Cu3O7-d Planar
 Junctions." To be published in Physica C (in press). Superconductivity
 Research Laboratory, International Superconductivity Technology Center
 (ISTEC), 10-13 Shinonome 1-chome, Koto-ku, Tokyo 135-0062, JAPAN;
 telephone +81 3 3536 5713; telefax +81 3 3536 5705; e-mail
 <a href="mailto:msato@istec.or.jp">msato@istec.or.jp.</a> Key words: thin films, Josephson effect, proximity
 effect, Shapiro steps. 74.50.+r; 74.80.Fp.
<p>
 Ravi-Persad Sawh, Roy Weinstein, Yanru Ren, Victor Obot, and Harald
 Weber, "Uranium Fission Fragment Pinning Centers in Melt-Textured YBCO."
 Submitted to the Proc. of the 6th Int. Conf. on Mater. and Mech. of
 Supercond. and High Temp. Supercond. (M^2S-HTSC-VI), Houston, Tex., Feb.
 20-25, 2000; to be published in Physica C. Contact Beam Particle
 Dynamics Group, University of Houston, 632 Science Research Bldg.,
 Houston, TX 77204-5506; telephone (713) 743-3600; telefax (713) 747-
 4526.
<p>
 Daniel E. Sheehy, Paul M. Goldbart, Joerg Schmalian, and Ali Yazdani,
 "Andreev Interferometry as a Probe of Superconducting Phase Correlations
 in the Pseudogap Regime of the Cuprates." Department of Physics and
 Materials Research Laboratory, University of Illinois at Urbana-
 Champaign, Urbana, IL 61801; e-mail <a href="mailto:d-sheehy@uiuc.edu">d-sheehy@uiuc.edu;</a> preprint also
 available at <a href="http://xxx.lanl.gov/abs/cond-mat/0001039">http://xxx.lanl.gov/abs/cond-mat/0001039.</a> 74.50.+r;
 74.40.+k; 74.72.-h.
<p>
 Hiroshi Shimahara and Satomi Hata, "Superconductivity in a Ferromagnetic
 Layered Compound." Department of Quantum Matter Science, ADSM,
 Hiroshima University, Higashi-Hiroshima 739-8526, JAPAN; e-mail
 <a href="mailto:simahara@minerva.ias.hiroshima-u.ac.jp">simahara@minerva.ias.hiroshima-u.ac.jp;</a> preprint also available at
 <a href="http://xxx.lanl.gov/abs/cond-mat/0001318">http://xxx.lanl.gov/abs/cond-mat/0001318.</a>
<p>
 U. Staub, L. Soderholm, S. Skanthakumar, R. Osborn, F. Fauth, and C.
 Ritter, "The Magnetic Properties of Pr in the Pb2Sr2PrCu3O8+d Cuprate."
 To be published in Physica C. Swiss Light Source, Paul Scherrer
 Institute, CH-5232 Villigen PSI, SWITZERLAND; e-mail <a href="mailto:urs.staub@psi.ch">urs.staub@psi.ch.</a>
 74.72.-h; 71.70.Ch; 75.25.+z; 74.62.Dh.
<p>
 M. Suenaga, T. Chiba, S. P. Ashworth, and D. O. Welch, "ac Losses in
 Stacked Bi2Sr2Ca2Cu3O10/Ag Tapes in Perpendicular Magnetic Fields."
 Submitted to J. Appl. Phys. Department of Applied Science, Brookhaven
 National Laboratory, Upton, NY 11973. 74.60.Jg; 74.72.Hs.
<p>
 G. A. Ummarino and R. S. Gonnelli, "s- and d-Wave Solution of Eliashberg
 Equations with Finite Bandwidth." To be presented at the 6th Int. Conf.
 on Mater. and Mech. of Supercond. and High Temp. Supercond. (M^2S-HTSC-
 VI), Houston, Tex., Feb. 20-25, 2000. INFM-Dipartimento di Fisica,
 Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino,
 ITALY; R. S. Gonnelli's e-mail <a href="mailto:gonnelli@polito.it">gonnelli@polito.it;</a> preprint also
 available at <a href="http://xxx.lanl.gov/abs/cond-mat/9912433">http://xxx.lanl.gov/abs/cond-mat/9912433.</a>
<p>
 G. A. Ummarino, R. S. Gonnelli, and D. Daghero, "Solution of Real-Axis
 Eliashberg Equations with Different Pair Symmetries and Tunneling
 Density of States." To be presented at the 6th Int. Conf. on Mater. and
 Mech. of Supercond. and High Temp. Supercond. (M^2S-HTSC-VI), Houston,
 Tex., Feb. 20-25, 2000. INFM-Dipartimento di Fisica, Politecnico di
 Torino, Corso Duca degli Abruzzi 24, I-10129 Torino, ITALY; R. S.
 Gonnelli's e-mail <a href="mailto:gonnelli@polito.it">gonnelli@polito.it;</a> preprint also available at
 <a href="http://xxx.lanl.gov/abs/cond-mat/9912432">http://xxx.lanl.gov/abs/cond-mat/9912432.</a>
<p>
 R. Weinstein, Y. Ren, R. Sawh, A. Gandini, W. Hennig, M. Murakami, T.
 Mochida, N. Chikumoto, N. Sakai, G. Krabbes, W. Bieger, D. Milliken, S.
 X. Dou, S. Toenies, M. Eisterer, and H. W. Weber, "Properties of HTS for
 Successful U/n Processing." To be presented at the 6th Int. Conf. on
 Mater. and Mech. of Supercond. and High Temp. Supercond. (M^2S-HTSC-VI),
 Houston, Tex., Feb. 20-25, 2000; to be published in Physica C. Contact
 Beam Particle Dynamics Group, University of Houston, 632 Science
 Research Bldg., Houston, TX 77204-5506; telephone (713) 743-3600;
 telefax (713) 747-4526.
<p>
 Chau-Yun Yang, Ataru Ichinose, S. E. Babcock, J. S. Morrell, J. E.
 Mathis, D. T. Verebelyi, M. Paranthaman, D. B. Beach, and D. K.
 Christen, "Microstructure of a High Jc, Laser-Ablated YBa2Cu3O7-d/Sol-
 Gel Deposited NdGaO3 Buffer Layer/(001) SrTiO3 Multi-Layer Structure."
 To be published in Physica C (in press). Contact S. E. Babcock, Applied
 Superconductivity Center and Department of Materials Science and
 Engineering, University of Wisconsin-Madison, 1500 Engineering Drive,
 Madison, WI 53706; telephone (608) 263-5696; telefax (608) 263-1087; e-
 mail <a href="mailto:babcock@engr.wisc.edu">babcock@engr.wisc.edu.</a> Key words: YBCO, sol-gel, buffer layer,
 coated conductors.
<p>
 B. Zeimetz, R. P. Baranowski, and J. E. Evetts, "Investigation of Local
 Current Flow in Polycrystalline, Anisotropic Superconductors Using
 Finite Element Simulation." Submitted to J. Appl. Phys. Department of
 Materials Science, Cambridge University, Pembroke Street, Cambridge CB2
 3QZ, UNITED KINGDOM; telephone +44 1223 334375; telefax +44 1223 334373;
 e-mail <a href="mailto:bpz20@cam.ac.uk">bpz20@cam.ac.uk.</a>
 <hr>
<p>
 COMING EVENTS
 (An * indicates a previously listed event. Also see complete listing of
 upcoming conferences and workshops at our Web site
 <a href="http://www.iitap.iastate.edu/htcu/comevents.html.">http://www.iitap.iastate.edu/htcu/comevents.html.)</a>
<p>
 *April 16 - 19, 2000: 6th Twente Workshop on Superconducting
 Electronics, Congress Center "Drienerburght," University of Twente,
 Enschede, The Netherlands. Aim of this meeting is an international
 exchange of latest results and new ideas on the electronic applications
 of superconductors focusing on the following areas of research: using
 fundamental aspects for new device concepts (e.g. pi junctions, qubits);
 relation between materials properties and transport; advanced circuitry;
 spin-dependent transport; and novel applications. Morning sessions
 devoted to invited talks with discussion breaks; afternoon sessions
 devoted to contributed papers. Abstract deadline, March 15, 2000. For
 information, contact Ingrid Oomen or Alexander Brinkman, Department of
 Applied Physics (TN/LT), University of Twente, P.O. Box 217, 7500 AE
 Enschede, The Netherlands; telephone +31 53 489 2806; telefax +31 53 489
 1099; e-mail <a href="mailto:i.oomen@tn.utwente.nl">i.oomen@tn.utwente.nl</a> or <a href="mailto:a.brinkman@tn.utwente.nl">a.brinkman@tn.utwente.nl.</a>
<p>
 *April 24 - 28, 2000: Superconducting and Related Oxides -- Physics and
 Nanoengineering IV, Marriott's Orlando World Center Resort and
 Convention Center, Orlando, Fla. Part of SPIE's 2000 AeroSense
 Symposium. Fourth in the series of SPIE conferences focused on basic
 issues in physics and materials science of high-temperature
 superconductors and related compounds that may be relevant for their
 applications in electronics, optics, and optoelectronics. Topics will
 include: a) structural, transport, magnetic, and thermal properties of
 thin films of cuprates and related compounds; b) homoepitaxy, new
 substrate materials, epitaxial and morphological properties, interface
 smoothness and disorder, layer thickness fluctuations, interdiffusion,
 and strain; c) proximity effects, surface and interface effects, and
 superconductors in contact with insulators, semiconductors, normal
 metals, ferro- and antiferromagnets, piezoelectrics, etc.; d) search for
 novel high-temperature superconducting phases by atomic engineering; e)
 electronic structure, charge redistribution, localization, single-
 particle and collective excitations, and Josephson phenomena in natural
 and artificial superlattices; f) novel device concepts, electric field
 effect in heterostructures, hybrid optoelectronic devices, and
 cryoelectronics. Three-day exhibition. Proceedings to be published.
 Contact SPIE, P.O. Box 10, Bellingham, WA 98227-0010; telephone (360)
 676-3290; telefax (360) 647-1445; e-mail <a href="mailto:OR@spie.org">OR@spie.org;</a> Web site
 <a href="http://www.spie.org/web/meetings/calls/or00/confs/OR15.html">http://www.spie.org/web/meetings/calls/or00/confs/OR15.html.</a>
<p>
 *May 24 - 27, 2000: Sixth Symposium on High Temperature Superconductors
 in High Frequency Fields (HTS-HF 2000), The Island of Capri, Naples,
 Italy. Organized by I.N.F.M. and Dipartimento Scienze Fisiche, and the
 University Federico. Aim of this biannual symposium is to bring
 together distinguished researchers involved in the study of the
 properties of high-temperature superconductors in rf and microwave
 fields, with emphasis on fundamental properties and material aspects,
 experimental methods, and market-emerging targets. Three areas have
 been identified as the main topics of the 2000 symposium: (1) Science
 and technology of HTS at microwave frequencies -- new ideas and novel
 materials; correlation between microwave properties and material
 structure, morphology, defects, and impact on devices; nonlinear
 effects, harmonic generation and inter-modulation distortion in devices,
 and understanding and standardization of measurements. (2) Microwave
 applications of HTS -- recent advances in telecommunication systems;
 tunable devices and totally agile superconducting systems; NMR and MRI
 applications; spatial probing; and cryopackag-ing issues. (3) Space
 applications of HTS -- state-of-the-art of the North American and
 European programs. Scientific program will include keynote lectures
 supplemented by poster sessions, and ample time will be given to
 discussions and socialization. Participation is by invitation only and
 is presently limited to about 80 attendants. Abstract deadline, March
 15, 2000. For information, contact Annamaria Mazzarella, Conference
 Secretariat; telephone +39 081-8534123 or -8661381; telefax +39 081-
 5267654; e-mail <a href="mailto:cib@secyann.cib.na.cnr.it">cib@secyann.cib.na.cnr.it.</a>
<p>
 June 18 - 23, 2000: European Conference on Energy Dispersive X-Ray
 Spectrometry (EDXRS 2000), Krakow, Poland. Aim of the conference is
 to bring together scientists working
 either in basic research in x-ray spectrometry, detectors and sources,
 or involved in applications of x-ray spectrometry or some of the related
 experimental techniques. Main topics: interaction of photons and
 particles with matter and modeling; new developments in instrumentation
 (instruments utilizing polarized radiation, synchrotron radiation and
 other x-ray sources, grazing angle spectrometers, portable instruments);
 energy dispersive x-ray detectors (cryo-detectors, low-Z detectors,
 Peltier-cooled detectors, dedicated pulse processing); quantitation and
 data handling (sample preparation, quality control and quality
 assurance, simulation, modeling, software); x-ray optics (capillaries,
 mirrors, multilayers, TXRF, imaging); microanalysis and elemental
 mapping (micro-XRF, micro-PIXE, EPMA); and x-ray spectrometry
 applications in life and environmental sciences, earth sciences, art and
 cultural heritage, material sciences, and industry. Abstract deadline,
 March 1, 2000. The official language of the Conference is English. For
 information, contact EDXRS-2000 Secretariat, Faculty of Physics and
 Nuclear Techniques, University of Mining and Metallurgy, Al. Mickiewicza
 30, 30-059 Krakow, Poland; telefax +48 12 6340010; Web site
 <a href="http://www.ftj">http://www.ftj.</a> agh.edu.pl/wfitj/conf/edxrs/.
<p>
 *July 3 - 28, 2000: United States Summer School in Condensed Matter and
 Materials Physics, Boulder, Colo. New summer school for graduate
 students and postdocs in condensed-matter and materials physics has been
 established and will be held annually in Boulder. This first one is
 entitled Introduction to Superconductivity: Fundamentals and
 Applications. Main themes of the school will be basic principles of
 superconductivity, quantum dynamics of vortices and electrons, vortices
 in D > 2 and critical phenomena in superconductors, high-temperature and
 other unconventional superconductors, physics and applications of vortex
 dynamics, nonequilibrium superconductivity, mesoscopic and nanoscale
 superconducting systems, materials, applications, and devices.
 Application deadline, May 1, 2000. Most local expenses will be covered
 by the summer school (supported by the National Science Foundation,
 University of Colorado at Boulder, NIST, and Lucent). For further
 information, contact Z. Tesanovic, Department of Physics and Astronomy,
 315 Bloomberg Center, Johns Hopkins University, 3400 North Charles
 Street, Baltimore, MD 21218-2686; telephone (410) 516-5391; telefax
 (410) 516-7239; e-mail <a href="mailto:cmsummer@pha.jhu.edu">cmsummer@pha.jhu.edu</a> or <a href="mailto:zbt@pha">zbt@pha.</a> jhu.edu. For
 details and application forms see Web site
 <a href="http://www.indiana.edu/~uscmpsc/">http://www.indiana.edu/~uscmpsc/.</a>
<p>
 *Aug. 1 - 4, 2000: Minisymposium on Correlation in Mesoscopic Systems,
 Miramare, Trieste, Italy. Objective is to bring together leading
 researchers actively working in the field of normal-metal mesoscopic
 systems and 2D metal-insulator transitions, in order to discuss the most
 recent developments and research directions. Topics are interaction in
 mesoscopic systems, 2D delocalization transition, and non-equilibrium
 meso-scopics. Scientists and physicists from all countries that are
 members of the UN, UNESCO or IAEA can attend the Minisymposium. Some
 funds are available for subsistence allowance to a limited number of
 participants from developing countries. No registration fee. Deadline
 for participation request, March 31, 2000. Request for participation
 obtainable via e-mail from <a href="mailto:smr1234@ictp.trieste.it">smr1234@ictp.trieste.it.</a> Contact Ms. E.
 Brancaccio, Minisymposium on Correlation in Mesoscopic Systems,
 International Centre for Theoretical Physics, Strada Costiera 11, I-
 34014 Trieste, Italy; telephone +39 040 2240284; telefax +39 040
 2245163; e-mail <a href="mailto:SMR1234@">SMR1234@</a> ictp.trieste.it; Web site <a href="http://www.ictp">http://www.ictp.</a>
 trieste.it/cgi-bin/ICTPsmr/mkhtml/smr2html.pl?smr1234/Bulletin.
<p>
 *Sept. 13 - 16, 2000: The Second International Conference on Inorganic
 Materials, University of California, Santa Barbara. Meeting will
 provide an opportunity to highlight recent developments and to identify
 emerging and future areas of growth in this field. Topics include
 electronic materials, structural materials and ceramics, biomaterials,
 intermetallics, catalytic and porous materials. Emphasis on oral
 presentations by invited speakers combined with extended poster
 sessions. Abstract deadline, February 25, 2000. Official language is
 English. A tabletop exhibition will run for the duration of the
 conference. For information, contact Sarah Wilkinson, Second
 International Conference on Inorganic Materials, Elsevier Science Ltd.,
 The Boulevard, Langford Lane, Kidlington, Oxford, OX5 1GB, United
 Kingdom; telephone +44 1865 843691; telefax +44 1865 843958; e-mail
 <a href="mailto:sm.wilkinson@elsevier.co.uk">sm.wilkinson@elsevier.co.uk.</a>
 <hr>
<p>
 FYI
 (High-Tc Update takes no responsibility for want ads listed in this
 section.)
<p>
 Position open: Postdoctoral research position available for study of
 the origin of nonlinearity in the microwave properties of HTS thin
 films. Supported by funding from the National Physical Laboratory.
 Interested candidates should have experience in working with
 superconducting materials at high frequencies and will join an
 established interdisciplinary research group at Imperial College,
 London. Close interaction with collaborators both in the UK and US.
 Position is available immediately; initial term is 18 months. Salary:
 16,286 Pounds plus London allowance. Application deadline, February 29,
 2000. To apply, send a full CV and list of references to L. F. Cohen,
 Imperial College, Blackett Laboratory, London SW7 2BZ, UNITED KINGDOM;
 email <a href="mailto:l.cohen@ic.ac.uk">l.cohen@ic.ac.uk.</a>
<p>
 Students who wish to pursue a Ph.D. in the superconductivity field are
 invited to apply to the Institute for Beam Particle Dynamics Group at
 the University of Houston. Work involves development of pinning centers
 by both chemical and irradiation methods, and currently concentrates on
 a variety of problems in Y123, Nd123, Sm123, and BiSCCO. The group also
 studies levitation, magnet arrays and bearings, and pulsed
 magnetization. Stipend of $15,000 per year. For information, contact
 Roy Weinstein, Institute for Beam Particle Dynamics, University of
 Houston, Houston, TX 77204-5506; telephone (713) 743-3600; telefax (713)
 747-4526; e-mail <a href="mailto:weinstein@">weinstein@</a> uh.edu.
<p>
 Positions open: Engineers or scientists needed for development of
 mechanical process optimization of powder-in-tube (PIT) Bi-2223 tapes.
 Work will involve R&D on optimization of mechanical deformation in PIT
 tapes, development of mechanical deformation equipment for alternative
 wire geometries, twisting and stranding processes, twisting and
 stranding equipment, and general support in mechanical design.
 Candidates must have a Ph.D. or M.Sc. in Mechanical Engineering and 1-3
 years industrial or research experience in mechanical processing.
 Experience with rolling and drawing processes, pocessing of powder, and
 industrial manufacturing experience desired. For information, contact
 Per Vase, Vice President Engineering, Nordic Superconductor Technologies
 A/S, Priorparken 685, 2605 Brondby, Denmark; telephone +45 43482508;
 cell phone +45 21714001; telefax +45 43482501; e-mail <a href="mailto:p.vase@nst.com">p.vase@nst.com.</a>
<p>
 <hr>
<p>
 High-Tc Update is the high-Tc superconductivity information exchange
 newsletter. Please send 1) preprints, reprints, and other research
 reports; 2) descriptions of on-going work; 3) meeting announcements and
 summaries.
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 The information contained herein is intended for limited distribution.
 Readers are expected to respect the rights of the authors.
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 Please address all contributions and inquiries to:
 Dr. Sreeparna Mitra, A219 Physics
 Ames Laboratory/Iowa State University
 Ames, Iowa 50011-3020
 Telephone: (515) 294-3877 Telefax: (515) 294-1134
 E-mail: <a href="mailto:MITRA@AMESLAB.GOV">MITRA@AMESLAB.GOV</a> or <a href="mailto:MITRA@IASTATE.EDU">MITRA@IASTATE.EDU</a>
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 Project Director/Editor: Sreeparna Mitra
 Science Editor: John R. Clem
 High-Tc Update, Vol. 14, #4, February 15, 2000.
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