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Note correction: The alkaline-earth cuprate studied by J. P. Hodges (Birmingham) et al. [see April 1 HTCU] was Sr0.8Ba1.2CuO3+d and not Sr0.08Ba1.2CuO3+d.
Vortices
Measurements of the [89]^Y NMR linewidth Delta-nu and spin-lattice relaxation rate T_1^[-1] have been performed by M. Corti (Pavia) et al. using an oriented powder sample of YBa2Cu4O8 (Tc = 81 K) in applied fields both parallel and perpendicular to c at 9.4 T and 5.9 T. The authors present evidence for the effects of thermal motion of vortices below Tc, and they use a simple model to derive the microscopic correlation times of the vortex motion.
Experimental and theoretical studies of the [1]^H NMR relaxation gamma = 1/T_1 in the organic superconductor BEDT in magnetic fields B perpendicular to the conducting planes have been carried out by H. Mayaffre (Orsay) et al. The curves gamma(T,B=const) show a pronounced peak, whose position T_[max](B) coincides with a vortex-lattice melting line revealed by other methods. The authors explain the results by suggesting that the relaxation comes from the Brownian motion of highly diffusive point defects (vacancies or interstitials) in decoupled 2D crystals of pancake vortices.
As described in a preprint by E. A. Jagla and C. A. Balseiro (Bariloche), the authors have used a three-dimensional stacked triangular network of Josephson junctions as a model to study the vortex structure in the mixed state of high-Tc superconductors. The authors find that the addition of disorder destroys the first-order melting transition that occurs for clean samples. The melting transition splits into two different continuous transitions, occurring at temperatures T_i and T_p (>T_i). At T_i the perpendicular-to-field superconductivity is lost, and at T_p the parallel-to-field superconductivity is lost. These results agree well with recent experiments in twinned YBa2Cu3O7-d.
The stability of the vortex configuration in thin superconducting strips under an applied field has been investigated by I. Aronson (Bar Ilan) and V. Vinokur (Argonne) analytically and by numerical solution of the time-dependent Ginzburg-Landau equation. The authors find that the surface barrier becomes unstable with respect to long-wavelength perturbations above some critical current I_c. At currents slightly above I_c, the vortex phase develops plastic flow, where large coherent pieces of lattice are separated by lines of defects and slide with respect to each other (ice-flow-like motion). At elevated current, a transition to elastic flow is observed.
One-dimensional numerical simulations of the pinned vortex lattice have been carried out by R. E. Gross and A. M. Campbell (Cambridge) using an inverted model in which widely spaced, weak point pinning centers are distorted by a rigid lattice. The authors find that this allows them to simulate a much larger array than if they had found the position of each vortex separately. The results are in agreement with the LarkinOvchinnikov theory of collective pinning. Quasistatic shifting of the pins over the rigid vortex lattice also allowed the size of avalanches in the flow state to be measured. The distribution of avalanche sizes displays power-law behavior over several decades.
The flow of 2D flux lines confined to narrow channels has been studied by M. H. Theunissen (Leiden) et al. using amorphous Nb3Ge channels between regions in which vortices are strongly pinned in NbN. In the solid, incommensurability between the lattice and channel width causes mobility oscillations as a function of magnetic field. In the liquid, the oscillations disappear, and the flow is controlled by the shear viscosity eta, whose value is determined as a function of field and temperature. Just above the melting transition, the shear viscosity diverges as eta proportional to xi_+^2(T,B), where xi_+ is the translational correlation length. The authors also find an indication for the hexatic-to-liquid transition.
The role of 2D vortex fluctuations in Bi2Sr2Ca2Cu3O10+d (Bi-2223) and YBa2Cu3O7-d (YBCO) thin films has been analyzed experimentally and theoretically by V. Persico (Napoli) et al. The resistance versus temperature and the current-voltage characteristics are discussed in terms of a Ginzburg-Landau Coulomb-gas model. The authors obtain new information about the interplane coupling (2D-3D crossover) in Bi-2223 and YBCO.
The stability of the vortex lattice in anisotropic superconductors has been investigated by A. M. Thompson and M. A. Moore (Manchester) using anisotropic London theory. By calculating the normal modes of the elasticity matrix, the authors find that the lattice is stable at large fields, but that instabilities occur when the field is reduced. The field at which these instabilities occur depends on the anisotropy parameter epsilon = 1/gamma and the angle theta at which the lattice is tilted away from the c axis. The findings support the picture that, in regions of the phase diagram where the vortex lattice is unstable, the vortices present are likely to exist in two distinct orientations.
A preprint by M. Wurlitzer (Leipzig) et al. reports studies of the hysteretic loss and shielding capability of flat Bi2Sr2CaCu2O8+d (Bi2212) and YBa2Cu4O8 (Y-124) crystals as a function of ac field (mu_0H <= 1 mT), frequency, and temperature at small dc fields (mu_0H_a < 1 mT) near the critical temperature Tc. The global ac field dependence of the susceptibility can be described in terms of a geometrical barrier model, in agreement with local permeability results. At temperatures very near Tc, however, the authors observe a crossover to diffusive behavior.
As shown by S. Dubois et al. (Pessac), the onset of the third harmonic susceptibility is the only appropriate criterion for determining the irreversibility line. The onset of chi" (or mu") does not appear at the same temperature in a dc magnetic field. The result is explained by flux-flow mechanisms: the chi" onset appears in a linear regime, while the chi_3 onset appears with nonlinear effects.
The ac response of the vortex liquid in a high-Tc superconducting cylinder in the parallel-field configuration has been examined theoretically by C.-J. Wu and T.-Y. Tseng (National Chiao-Tung). The authors find that the permeability is dominated by two frequencydependent penetration depths. As a function of frequency, the authors find two peaks in mu", the imaginary part of the permeability. The peak at high frequency is associated with the contribution of the normal fluid. The authors also find some basic differences between the ac permeabilities of a cylinder and a slab.
NdBa2Cu3O7-d
Remarkably high irreversibility fields in NdBa2Cu3O7-d (NBCO or Nd-123) single crystals are reported by T. Wolf et al. (Karlsruhe). The furnace atmosphere was reduced to 50-100 mbar air to avoid Nd substitution at the Ba site. The grown crystals of size up to 6 x 6 x 3 mm^3 were oxidized in flowing oxygen of 1 bar between 600^oC and 350^oC for 1000 h, and then in a static oxygen atmosphere of 175 bar between 480^oC and 280^oC for 300 h. The irreversibility field B_[irr] parallel to the c axis of the crystal reaches 12.1 T at 78.5 K using the criteria of 100 A/cm^2 and 10^[-2] microvolts/cm. A linear extrapolation to 77 K yields an irreversibility field of 13.4 T, which is roughly twice that of YBa2Cu3O7-d. This field is even higher than the upper critical field of commercial NbTi at 4.2 K, suggesting a huge potential for NBCO if it can be made in the form of tapes or wires.
The authors stress that the large value of B_[irr] (12.1 T at 78.5 K) is not simply a result of the higher transition temperature of NBCO [(95.5+-0.3) K], because in YBa2Cu3O7-d at the same reduced temperature (77 K) B_[irr] = 10.3 T. The critical current density Jc, which is not yet optimized, has a maximum value of 3.5 x 10^4 A/cm^2 at 4.6 T and 77 K, and is still above 10^4 A/cm^2 at 10 T. A small reduction of the oxygen content increases Jc and slightly reduces B_[irr](T) without changing Tc. This observation points to oxygen vacancies being responsible for the peak in Jc vs. B, as in pure YBa2Cu3O7-d crystals.
Single crystals of NdBa2Cu3O7-d also have been grown by M. Nakamura (SRL-ISTEC) et al. using the top-seeded solution-growth method in oxygen partial pressures of 0.01 atm, 0.21 atm, and 1.00 atm. A Ba-Cu-O solvent with a Ba:Cu ratio of 3:5 was used in a Nd2O3 crucible. Nd was supplied by the reaction between the molten solvent and the crucible. Measurements of the dc magnetization using a SQUID magnetometer showed a steep transition at 96 K for the Nd-123 crystal grown in P(O2) = 0.01 atm. The other crystals showed broad transitions at 92 K [P(O2) = 0.21 atm] and 88 K [P(O2) = 1.00 atm]. The authors conclude that to achieve high Tc in Nd-123 crystals, a low oxygen partial pressure during crystal growth is effective in minimizing the substitution of Nd ions onto Ba sites.
YBa2Cu3O7-d
Very high trapped magnetic fields, 10.1 T at 42 K (not 4.2 K!), are reported by R. Weinstein (Houston) et al. in mini-magnets fabricated from four disks of proton-irradiated, melt-textured Y-123, each 2 cm in diameter and 0.8 cm thick. The authors stress that this is the highest trapped field ever achieved in any material at any temperature. To achieve such trapped fields, procedures to avoid cracking, quenches, and creep must be employed.
A preprint by D. C. Ling et al. (Wayne State) reports the observation of microwave-induced dc voltages in a YBa2Cu3O7-d single crystal. The dc voltages were produced along the c axis, with or without a dc bias current, in the presence of standing waves near the end of an X-band (812 GHz) waveguide. Without a dc bias current, the induced voltages are attributed to the inverse ac Josephson effect, which requires the presence of both E and H microwave fields.
Bi Cuprates
Angle-resolved photoemission experiments by A. G. Loeser et al. (Stanford) have revealed evidence for an energy gap in the normal-state excitation spectrum of the cuprate superconductor Bi2Sr2CaCu2O8+d (Bi2212). This gap exists only in underdoped samples, and closes around the doping level where Tc is maximized. The momentum dependence and the magnitude of the gap closely resemble those of the d_[x^2-y^2] gap observed in the superconducting state. As well as presenting photoemission data, the authors survey other experiments that produced results consistent with a gap in the normal state, and they review some possible theoretical explanations.
A preprint by D. S. Marshall (Stanford) et al. reports angle-resolved photoemission studies on Bi2Sr2Ca1-xDyxCu2O8+d and oxygen-depleted Bi2Sr2CaCu2O8+d investigating the electronic structure changes above Tc in materials with hole-doping levels ranging from insulating to slightly overdoped. Near optimal hole doping, the Fermi surface is large and consistent with band calculations. In slightly underdoped samples with Tc = 60-70 K, portions of this Fermi surface are not seen. This change is related to the opening of an energy gap near (pi,0) above Tc.
Measurements of the reversible magnetization of c-axis-oriented superconducting Bi2Sr2Ca2Cu3O10+d (Bi-2223) tapes, irradiated with 5.8 GeV Pb ions to produce columnar defects along the c axis, are reported by Q. Li (Brookhaven) et al. The magnetization M as a function of field and temperature were measured for both unirradiated and irradiated samples with matching fields of B_[phi] = 1.28 T, 2.0 T, and 4 T. In contrast to the conventional lnB dependence of the reversible M in the London regime, the field dependence of M for the irradiated samples shows a large reduction of M at B <= B_[phi], while a maximum appears at B > B_[phi]. The authors explain this field dependence in terms of the London model, modified by the localization of vortex lines in the columnar defects, and they use this picture to obtain the single-vortex columnar-defect pinning energy.
Hg Cuprates
A preprint by X. S. Wu (Nanjing) et al. reports that substitution of Pb for Hg in the HgBa2Ca2Cu3O8+d (Hg-1223, Tc ~~ 135 K) results in an increase of the magnetically determined superconducting transition temperature to Tc = 143 K (but zero-resistance Tc = 135 K) for samples with a nominal composition of Hg0.7Pb0.3Ba2Ca2Cu3O8+d. The lattice parameter changes resulting from the Pb substitution are too small to explain the Tc change as arising from an effective pressure change.
Borocarbides
Small-angle-neutron-scattering (SANS) experiments by U. Yaron (Bell Labs) et al. have revealed a square vortex lattice, rather than a hexagonal one, in the magnetic superconductor ErNi2B2C (superconducting Tc = 10.5 K, antiferromagnetic Neel temperature T_N = 6 K). Even more interesting, the authors find a significant coupling between the magnetic ordering and the vortices, as evidenced by a rotation of the vortex lines away from the direction of the applied field below the Neel transition, as well as disordering of the vortex lattice. The authors emphasize that these results demonstrate a direct coupling between the magnetic order parameter and the vortex lattice structure.
Detailed measurements by P. C. Canfield et al. (Ames Lab, Iowa State) of the magnetic-field- and temperature-dependent anisotropic magnetization M(H,T) in single-crystal ErNi2B2C indicate that there is a phase transition to a magnetically ordered ground state with a weak ferromagnetic component of 0.33 mu_B/Er for T < 2. 3 K. This ordering is similar to the transition to weak ferromagnetism seen in TbNi2B2C, but, unlike the behavior in TbNi2B2C, the ferromagnetic component exists in ErNi2B2C at temperatures and fields that are well below Tc and H_[c2]. The authors conclude that superconductivity and weak ferromagnetism coexist in ErNi2B2C for T < 2.3 K and H < 12 kG.
Thin Films
A systematic study of the surface resistance of conducting materials for various thicknesses and resistivities in the normal skin-effect regime has been carried out by S. E. Lofland et al. (Maryland). For samples thicker than the electromagnetic skin depth, the surface resistance R_s is proportional to rho^[1/2], where rho = 1/sigma is the resistivity. However, for samples thinner than the skin depth, there are two regimes: (a) R_s proportional to rho and (b) R_s proportional to sigma, which holds for the least conducting films, the crossover occurring at about 1 milliohm-cm at 10 GHz. In all cases where case b was observed in the normal state, R_s was found to have a peak in the superconducting state.
A preprint by J.-P. Locquet (IBM-Zurich) et al. reports the use of an electrochemical oxidation/reduction technique to pattern superconducting regions into an otherwise insulating matrix. On a microscopic scale the extra oxygen introduced creates metallic and/or superconducting regions in the insulating matrix. The technique is well suited for the high-Tc oxides but can be used for other oxides as well. A main feature of this process is that it does not induce significant height differences, as do most other lithography methods.
A scanning Hall probe has been used by H. Darhmaoui (Alberta) et al. to investigate the temperature dependence of the penetration of magnetic flux into YBa2Cu3O7-d disk-shaped thin films at low magnetic fields. The authors studied the conditions characteristic of complete and incomplete flux penetration.
The ac susceptibility of structured YBa2Cu3O7-d thin films in perpendicular ac magnetic fields between 1 micro-Tesla and 1 mT has been studied by M. Wurlitzer et al. (Leipzig). The ac field dependence can be well understood using recently published theories for the ac susceptibility of thin strips and disks in ac transverse fields.
Applications
As reported by N. J. Wu et al. (Houston), ferroelectric Pb(Zr0.52Ti0.48)O3 (PZT) (001) and (Mn,Sn)-doped PZT (PMSZT) (001) thin films have been integrated with high-Tc superconducting c-oriented YBa2Cu3O7-d films for use as infrared detectors. However, the YBCO thin films in the heterostructure were used here not for their superconducting properties but for their IR reflector-conductive electrode properties and as an atomic template for PZT/PMSZT epitaxial growth. The authors believe that PZT/YBCO and PMSZT/YBCO heterostructures are suitable materials for use in infrared detectors at temperatures above room temperature.
Theory
A paper by M. Cini and A. Balzarotti (Roma) proposes a configurationinteraction that leads to hole pairs with zero repulsion energy that are exact eigenstates of the two-band Hubbard hamiltonian. The two-hole pairs have [1]^B_2(xy) symmetry and arise from degenerate states at the Fermi level; the authors show that they must exist independently of the band filling. To discuss the possible relevance of these states to the problem of pairing in high-Tc superconductors, the authors solve fiveand nine-site model clusters with four holes. The quasiparticles become dressed by the interaction with the background holes, and they pair with a set of valence-band parameters that are well-established for the highTc cuprates. The theory yields binding energies of the correct order of magnitude, a [1]^B_1(x^2-y^2) symmetry of the order parameter, and the singlet-triplet energy separation of the Cooper pairs.
A theoretical analysis of angle-resolved photoemission (ARPES) experiments in the superconducting state of the high-Tc copper oxides has been carried out by R. Fehrenbacher (MPI-Stuttgart). It is based on a phenomenological weak-coupling BCS model that incorporates the experimental normal-state dispersion extracted from ARPES, and nonmagnetic impurity scattering in the presence of a d_[x^2-y^2] order parameter.
A paper by M. R. Norman (Argonne) and A. H. MacDonald (Indiana) reports on a numerical study intended to examine the possibility that magnetic oscillations persist in type-II superconductors beyond the point where the pairing self-energy exceeds the normal-state Landau-level separation. The authors find that the magnetic oscillations are strongly suppressed once the pairing self-energy exceeds the Landaulevel separation.
An analysis by S. A. Wolf (NRL) et al. of the temperature dependence of the upper critical field in several cuprate families leads to the conclusion that magnetic impurities are present even in samples with the maximum observed value of Tc. The authors introduce an intrinsic Tc (T_[c;intr]), which is the value of Tc in the absence of magnetic impurities. The authors conclude that the maximum value of T_[c;intr] at the optimum doping level is similar for different cuprates and has the value 160-170 K, which is viewed as an upper limit of Tc for the cuprates.
A preprint by D. R. Nelson (Harvard) discusses the conditions under which collections of flexible lines with repulsive pairwise interactions undergo melting, like ice, into a liquid that is denser than the solid phase. The author finds that such ice-like melting should occur generically for flexible lines with sufficiently long-range interactions.
Other Activities
Two preprints by H. A. Blackstead (Notre Dame) and J. D. Dow (Arizona State) present arguments that superconductivity in the cuprates originates not from the CuO2 planes but from the charge-reservoir regions.
Muon-spin-rotation measurements have been used by C. Bernhard (Konstanz) et al. to study the suppression of the condensate density n_s upon Zn substitution in underdoped, optimally doped, and overdoped Y0.8Ca0.2Ba2(Cu1-yZny )3O7-d and La1.79Sr0.21Cu1-yZnyO4. The rapid initial decrease of n_s is inconsistent with s-wave pairing and magnetic scattering but points towards a d-wave pairing state with nonmagnetic scattering in the unitarity limit.
A preprint by U. Staub (PSI-Villigen) et al. reports on Tb spin correlations in the high-Tc superconductor Pb2Sr2Tb0.5Ca0.5Cu3O8 determined by high-resolution neutron spectroscopy and neutron diffraction.
A laser-cutting technique has been used by T. Schuster (MPI-Stuttgart) et al. to pattern high-temperature superconducting DyBa2Cu3O7-d (DBCO), YBa2Cu3O7-d (YBCO), and Bi2Sr2CaCu2O8+d (Bi-2212) single crystals into various shapes with high precision. The low mean laser power of 135 mW enabled the authors to produce cuts of arbitrary shape without adversely affecting the superconducting parameters. This was shown by local magneto-optical observations of magnetic flux distributions.
Two papers in this issue discuss persistent photoconductivity in oxygendeficient cuprates. T. Endo et al. (UC-San Diego) measured the spectral dependency of the persistent photoconductivity in GdBa2Cu3O6.3 from the near infrared to the ultraviolet energy range. The excitation efficiency was found to be strongly enhanced for a photon energy of 4.1 eV. Photons with this energy create electron-hole pairs close to oxygen vacancies in the CuO chain layers. D. C. Chew (New Jersey Institute of Technology) et al. have found support for an oxygen-defect mechanism for persistent photoconductivity in investigations of laser-ablated YBa2Cu3Ox thin films, their compositions, photoluminescence spectra, and infrared spectroscopy. The model is that oxygen vacancies act as weakly luminescent F-centers and F^+-centers under illumination. Upon infrared illumination, the trapped electrons are photoexcited, resulting in a partial quenching of the persistent photoconductivity state.
Experiments by D. J. Thompson et al. (Wayne State) have confirmed that the paramagnetic Meissner effect (PME) in Nb is sensitive to surface features. By implanting Kr ions within 120 nm of the surfaces of diskshaped Nb samples, the authors found that the low-field magnetization in a field-cooling measurement is positive below the superconducting transition temperature Tc ~~ 9.2 K. By contrast, the field-cooled magnetization on similar disks prior to ion implantation was diamagnetic. In general, the authors find that the PME in these Nb disks results from the interplay of the sample geometry, a local Tc variation, and strong flux pinning from surface defects.
Theoretical calculations of phase locking in a simple two-dimensional two-loop Josephson-junction array have been carried out by M. Basler et al. (Jena). The authors find that in the stable oscillation regime the two loops oscillate with a phase shift of pi (i.e., anti-phase locking). This result may explain the low radiation output experimentally obtained to date in two-dimensional Josephson-junction arrays.
Overviews
A review of the superconducting magnetic properties of the doped fullerenes has been prepared by V. Buntar and H. W. Weber (AtominstitutWien). Experimental results on the main superconducting properties, including the critical fields and characteristic lengths, are critically examined. Different methods to evaluate the lower critical field are discussed. Experimental data on properties connected to flux pinning, including the critical current density, irreversibility line, and pinning force, are summarized (210 refs.).
A preprint by M. Cardona et al. (MPI-Stuttgart) briefly reviews the use of Raman spectroscopy to determine the basic properties and characterize the high-Tc superconductors. The authors emphasize the role of phonons in YBa2Cu3O7-d and the Hg-based cuprates (31 refs.).
Theses
The growth of extremely flat semiconductor and superconductor layers by liquid-phase epitaxy (LPE) is examined in H. J. Scheel's Tohoku University Doctor of Engineering thesis. The author describes the achievement of flat surfaces of YBa2Cu3O7-d and NdBa2Cu3O7-d with interstep distances between 0.5 micrometers and 3 micrometers. Further development should lead to interstep distances of 10 micrometer (134 refs.). Further details about the use of LPE to produce flat surfaces of YBCO are given in the preprint by C. Klemenz and H. J. Scheel (SFITLausanne).
A new method to study high-reflectance materials in the far infrared (FIR) is demonstrated and applied to high-Tc superconductors in the Universite Henri Poincare, Nancy 1, Ph.D. thesis of M. Tazawa. The thesis is in French, with a 19-page English abstract. To explain the data for the FIR properties of an YBa2Cu3O7-d film deposited on an MgO single crystal, the author uses a two-fluid model to determine the surface resistance, the London penetration depth, the performance of a Fabry-Perot interferometer with YBa2Cu3O7-d films as resonance mirrors, and other properties (97 refs.).
Contributed by John R. Clem
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 printing and mailing are welcome.
This section describes progress in manufacturing, product development, and technology transfer in the high-Tc superconductivity field. Please send your contributions (product development information, news regarding technology transfer efforts, or any information you would like to share about your corporation or laboratory) to the editor.
A strategic alliance was formed between American Superconductor Corp. (ASC) and the Electric Power Research Institute (EPRI) to develop and commercialize the next generation HTS wire to be used in products for electricity production, transmission, and use. An initial focus for the alliance will be the research advances demonstrated in the ion-beamassisted deposition (IBAD) HTS wire technology demonstrated at the Los Alamos National Lab. The alliance is projected to extend for four years, program details will depend on progress achieved during the preliminary two-year phase. ASC will receive exclusive marketing and manufacturing rights from EPRI to technologies developed in the alliance program. To carry out its goals, the alliance will work with the Los Alamos and Lawrence Berkeley National Labs, the Applied Superconductivity Center at the University of Wisconsin, Inco Alloys International, and Stanford University. Plans are also in progress to work in collaboration with the Wright Laboratory (DOD), MIT, and the Texas Center (Houston). The alliance and its broad-based team will focus on choosing those processes showing greatest probability for success in scaling up of the coated-conductor technology to high-volume, low-cost manufacturing, and aim for the end result of more efficient, lightweight, electric power products offering performance advantages for utilities and the industrial sector. For further information, contact Lori Telson, Electric Power Research Institute (EPRI), Palo Alto, CA 94303; telephone (415) 855-2272.
Introduction of a new superconducting NMR probe was announced by Varian Associates and Conductus, Inc., which the companies pronounce as one of the first HTS products designed to replace conventional technology used in the pharmaceutical and chemical industries. The product, known as SuperProton.nmr probe, is exclusively sold by Varian Associates and utilizes rf coils made of YBCO. Measurements show an increase in the sensitivity by a factor of four in comparison to traditional probes, which allows for analysis of much smaller quantities of new products and samples that are difficult or expensive to obtain. Additionally, significant time savings are achieved because the probe's improved sensitivity can reduce data acquisition times by a factor of 16 for most applications. The SuperProton.nmr probe is the result of a joint development project between Varian and Conductus, and is manufactured by Conductus at its Sunnyvale, California facility. For further information, contact Irv Hipschman, Conductus, Inc., 969 West Maude Ave., Sunnyvale, CA 94086; telephone (408) 523-9437; telefax (408) 5239999; e-mail hipschman@conductus.com.
Contributed by Sreeparna Mitra
I. Aranson and V. Vinokur, "Surface Instabilities and Plastic Deformation of Vortex Lattices." Bar Ilan University, Ramat Gan 52900, ISRAEL. 74.60.Ge; 68.10.-m; 05.60.+w.
V.P.S. Awana, J. Albino Aguiar, S. K. Malik, W. B. Yelon, and A. V. Narlikar, "Superconductivity and Structural Aspects of Y1-xCaxBa2Cu3O7-d with Variable Oxygen Content." To be published in the Proc. of the 10th Anniv. Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Departamento de Fisica, Universidade Federal de Pernambuco, 50670-901 Recife PE, BRAZIL; telefax +55 81 271 0359; e-mail awana@npd.ufpe.br.
V.P.S. Awana, S. K. Malik, and W. B. Yelon, "Structural Aspects and Superconductivity in Oxygen Deficient Y1-xCaxBa2Cu3O7-y (y ~~ 0.3) System: A Neutron Diffraction Study." To be published in Physica C. Departamento de Fisica, Universidade Federal de Pernambuco, 50670-901, Recife PE, BRAZIL; telefax +55 81 271 0359; e-mail awana@npd.ufpe.br.
M. Basler, W. Krech, and K. Yu. Platov, "Anti Phase Locking in a TwoDimensional Josephson Junction Array." Submitted to Appl. Phys. Lett. Institut fuer Festkoerperphysik, Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, D-07743 Jena, GERMANY; telephone +49 3641 635775; telefax +49 3641 6 35744; e-mail pmb@rz.uni-jena.de; preprint also available at cond-mat@xxx.lanl.gov (#9603041). 74.50.+r.
C. Bernhard and J. L. Tallon, "The Thermoelectric Power of Y1xCaxBa2Cu3O7-d Contributions from CuO2 Planes and CuO Chains." Submitted to Phys. Rev. B, March 13, 1996. Fakultaet fuer Physik, Universitaet Konstanz, Postfach 5560, D-78434 Konstanz, GERMANY; telephone +49 7531 88 3858; telefax +49 7531 88 3090; e-mail christian.bernhard@uni-konstanz.de. 74.72.Bk; 74.25.Fy; 74.25.Dw; 74.62.Dh.
C. Bernhard, J. L. Tallon, C. Bucci, R. De Renzi, G. Guidi, G.V.M. Williams, and Ch. Niedermayer, "Suppression of the Superconducting Condensate in the High-Tc Cuprates by Zn Substitution and Overdoping: Evidence for an Unconventional Pairing State." Submitted to Phys. Rev. Lett., Feb. 6, 1996. Fakultaet fuer Physik, Universitaet Konstanz, Postfach 5560, D-78434 Konstanz, GERMANY; telephone +49 7531 88 3858; telefax +49 7531 88 3090; e-mail christian.bernhard@uni-konstanz.de. 74.20.-z; 74.25.Nf; 74.62.Dh; 76.75.+i.
Howard A. Blackstead and John D. Dow, "Dramatic Evidence of ChargeReservoir, Polarization-Pairing, High-Temperature Superconductivity." To be published in Oxide Superconductors: Physics and Nanoengineering II, edited by D. Pavuna and I. Bozovic, Vol. 2697 (SPIE, Bellingham, 1996). Department of Physics, University of Notre Dame, Notre Dame, IN 46556.
Howard A. Blackstead and John D. Dow, "Hypercharged Copper, Hypocharged Oxygen, and High-Temperature Superconductivity." To be published in Oxide Superconductors: Physics and Nanoengineering II, edited by D. Pavuna and I. Bozovic, Vol. 2697 (SPIE, Bellingham, 1996). Department of Physics, University of Notre Dame, Notre Dame, IN 46556.
V. Buntar and H. W. Weber, "Magnetic Properties of Fullerene Superconductors." To be published in Supercond. Sci. & Technol. Atominstitut der OEsterreichischen Universitaeten, Schuettelstrasse 115, A-1020 Wien, AUSTRIA; telephone +43 1 72 701 296; telefax +43 1 72 89 220; e-mail buntar@ati.ac.at.
L. Buschmann, H. Hoffschulz, J. Dressen, H. Stahl, B. Decker, F. Nouvertne, R. Barth, B. Spangenberg, H. Kurz, and G. Guentherodt, "Preparation of Superconducting Nanometer Structures by Means of Scanning Tunneling Microscopy and of Layer-by-Layer MBE." To be published in Oxide Superconductors: Physics and Nanoengineering II, edited by D. Pavuna and I. Bozovic, Vol. 2697 (SPIE, Bellingham, 1996). 2. Physikalisches Institut, RWTH Aachen, D-52056 Aachen, GERMANY.
P. C. Canfield, S. L. Bud'ko, and B. K. Cho, "Possible Co-existence of Superconductivity and Weak Ferromagnetism in ErNi2B2C." To be published in Physica C, May 10, 1996. Ames Laboratory and Department of Physics and Astronomy; Iowa State University, Ames, IA 50011; telephone (515) 294-6270; telefax (515) 294 0689; e-mail canfield@ameslab.gov.
Manuel Cardona, Xingjiang Zhou, and Thomas Strach, "Raman Spectroscopy: Phonons." Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, GERMANY; telephone +49-711-6860710; telefax +49-711-6787-934; e-mail cardona@cardix.mpistuttgart.mpg.de.
Janina Ceremuga and Jerzy Krupka, "Dielectric Resonators for Microwave Characterization of High Temperature Superconductors." Presented at the SPIE Photonics West '96 Conf., San Jose, CA, Jan. 30-Feb. 2, 1996; to be published in Oxide Superconductors: Physics and Nanoengineering II, edited by D. Pavuna and I. Bozovic, Vol. 2697 (SPIE, Bellingham, 1996). Department of Electrical and Computer Engineering, James Cook University of North Queensland, Townsville Q4811, AUSTRALIA.
D. C. Chew, J. F. Federici, J. Gutierrez-Solana, G. Molina, W. Savin, and W. Wilber, "Defect Mechanism of Photoinduced Superconductivity in YBa2Cu3Ox." To be published in Spectroscopic Studies of Superconductors, edited by I. Bozovic and D. van der Marel, Vol. 2696 (SPIE, Bellingham, 1996). Department of Physics, New Jersey Institute of Technology, Newark, NJ 07102. Key words: YBa2Cu3Ox, persistent photoconductivity, photoinduced superconductivity, photoluminescence, oxygen defects, quenching.
Michele Cini and Adalberto Balzarotti, "Two-Hole Quasiparticles and Pairing in the Hubbard Model of High-Tc Superconducting Cuprates." To be published in J. Phys. INFM, Dipartimento de Fisica, Universita di Roma Tor Vergata, Via della Ricerca Scientifica, I-00133 Roma, ITALY. 74.72-h; 31.20.Tz; 74.20.-z.
M. Corti, B. J. Suh, F. Tabak, A. Rigamonti, F. Borsa, M. Xu, and B. Dabrowski, "Flux Lines Dynamics in YBa2Cu4O8 from [89]^Y NMR." Submitted to Phys. Rev. B. Department of Physics, A. Volta, Unita INFM and Sezione INFN di Pavia, Via Bassi 6, I-27100 Pavia, ITALY; B. J. Suh's telephone at Ames Lab, Ames, IA (515) 294-4908; e-mail bsuh@ameslab.gov. 74.60.Ge; 74.25.Ha; 74.25.Jb; 74.25.Nf.
Anne-Marie Dare, Y. M. Vilk, and A.-M.S. Tremblay, "Crossover from Twoto Three-Dimensional Critical Behavior for Nearly Antiferromagnetic Itinerant Electrons." Preprint #CRPS-96-02. Departement de Physique and Centre de Recherche en Physique du Solide, Universite de Sherbrooke, Sherbrooke, Quebec J1K 2R1, CANADA; A.-M.S. Tremblay's e-mail tremblay@physique.usherb.ca. 75.10.Lp; 71.27.+a; 71.10.+x; 74.72.-h.
H. Darhmaoui, J. Jung, J. Talvacchio, M.A.-K. Mohamed, and L. Friedrich, "Temperature Dependence of the Magnetic-Flux-Penetration into DiskShaped Y1Ba2Cu3O7-d Thin Films." To be published in Phys. Rev. B, May 1, 1996. Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1, CANADA.
S. Dubois, F. Carmona, and S. Flandrois, "Irreversibility Line of YBaCuO Sintered Ceramics, YBaCuO Single Crystal and Superconducting Composites Studied by ac Susceptibility and Transport Measurements." To be published in Physica C, Vol. 260 (in press). Unite PCPM, Bat. Boltzmann, Place Croix du Sud 1, B-1348 Louvain la Neuve, BELGIUM. Key words: irreversibility line, superconducting composites, ac susceptibility, magneto-transport measurements.
T. Endo, J. Santamaria, A. Hoffmann, and Ivan K. Schuller, "Enhancement of Persistent Photoconductivity by UV Excitation in GdBa2Cu3O6.3." Submitted to Phys. Rev. B. Contact A. Hoffmann, Department of Physics 0350, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0350; telephone (619) 534-7161; telefax (619) 534-0173; e-mail hoffmann@ucsd.edu. 73.50.Gr; 73.50.Pz; 74.76.Bz.
R. Feenstra, S. J. Pennycook, M. F. Chisholm, N. D. Browning, J. D. Budai, D. P. Norton, E. C. Jones, D. K. Christen, T. Matsumoto, and T. Kawai, "Defect Formation and Carrier Doping in Epitaxial Films of the Infinite Layer Compound." To be published in Oxide Superconductors: Physics and Nanoengineering II, edited by D. Pavuna and I. Bozovic, Vol. 2697 (SPIE, Bellingham, 1996). Solid State Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6057. Key words: cuprate superconductors, infinite-layer compound, atomic-layer epitaxy, electron microscopy, scanning tunneling microscopy, oxidation-reduction annealing.
R. Fehrenbacher, "Effect of Non-Magnetic Impurities on the Gap of a d_[x^2-y^2] Superconductor as Seen by Angle-Resolved Photoemission." Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstr. 1, D-70569 Stuttgart, GERMANY; e-mail rfehren@audrey.mpi-stuttgart.mpg.de.
K. C. Goretta, J. L. Routbort, R. L. Thayer, J. P. Carroll, J. Wolfenstine, J. Kessler, and J. Schwartz, "Deformation of Ag/1.2 at.% Mg." Submitted to Physica C. Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov.
Tomoko Goto, "Critical Current Density of Filamentary Y123 Superconductor." To be published in Physica C, Vol. 262 (in press). Department of Materials Science & Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466, JAPAN; telephone +81 52 735 5265; telefax +81 52 735 5294; e-mail zwgoto@mse.nitech.ac.jp.
Tomoko Goto, "Critical Current Density of Solution-Spun (Hg,Re0.2)Ba2Ca2Cu3Ox Filament." Submitted to Physica C. Department of Materials Science & Engineering, Nagoya Institute of Technology, Gokisocho, Showa-ku, Nagoya 466, JAPAN; telephone +81 52 735 5265; telefax +81 52 735 5294; e-mail zwgoto@mse.nitech.ac.jp.
Tomoko Goto and Eiji Sakai, "Superconducting Properties of Hg(Ba,Sr)2CaCu2ReOx Filament Produced by Solution Spinning." Department of Materials Science & Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466, JAPAN; telephone +81 52 735 5265; telefax +81 52 735 5294; e-mail zwgoto@mse.nitech.ac.jp.
R. E. Gross and A. M. Campbell, "Numerical Calculation of Elastic Pinning Parameters by Point Pins." To be published in Physica C, Vol. 333 (in press). Interdisciplinary Research Centre in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE, UNITED KINGDOM; telephone +44 1223 337078; telefax +44 1223 337074; e-mail reg1002@cus.cam.ac.uk. Key words: pinning models, collective pinning, avalanches.
Naomichi Hatano and David R. Nelson, "Localization Transitions in NonHermitian Quantum Mechanics." Lyman Laboratory of Physics, Harvard University, Cambridge, MA 02138. 05.30.Jp; 72.15.Rn; 74.60.Ge.
V. A. Ivanshin, R. Schauwecker, M. Warden, P. Erhart, H. Keller, H.-J. Guentherodt, H. P. Lang, and V. Thommen-Geiser, "Microwave Studies of the Superconducting State in Rb3C60." To be published in Physica C, Vol. 260 (in press). Faculty of Physics, Kazan State University, 420008 Kazan, RUSSIA; telefax +7 84 32 380 994; e-mail ivanshin@phys.ksu.ras.ru.
E. A. Jagla and C. A. Balseiro, "Effect of Disorder on the VortexLattice Melting Transition." Comision Nacional de Energia Atomica, Centro Atomico Bariloche and Instituto Balseiro, 8400 S. C. de Bariloche, ARGENTINA.
G. Jakob, U. Frey, M. Meffert, P. Haibach, K. UEstuener, and H. Adrian, "Josephson Junctions and SQUIDs Based on Artifical Grain Boundaries in Bi2Sr2Ca2Cu3O10 Thin Films." To be published in Oxide Superconductors: Physics and Nanoengineering II, edited by D. Pavuna and I. Bozovic, Vol. 2697 (SPIE, Bellingham, 1996). Johannes-Gutenberg Universitaet Mainz, D-55099 Mainz, GERMANY. Key words: high-Tc superconducting thin-film devices, grain-boundary Josephson junctions, Bi2Sr2Ca2Cu3O10.
R. Jammy, A. N. Iyer, M Chudzik, U. Balachandran, and P. Haldar, "Processing and Properties of Ag-Clad BSCCO Superconductors." To be published in the Proc. of the 10th Anniv. Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov.
R. Jammy, A. N. Iyer, J. Y. Huang, M. Chudzik, U. Balachandran, and P. Haldar, "Recent Developments in Fabrication and Properties of Ag-Clad BSCCO Conductors." To be published in the Proc. of TMS 1996 Ann. Mtg., Feb. 4-8, 1996, Anaheim, CA. Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov.
L. Jansen and R. Block, "Effect of Pressure and of Oxygen Content on Superconductivity in the Cuprate HgBa2CuO4+d: A Quantative Analysis Based on Indirect-Exchange Pairing." To be published in Physica A. Theoretische Physik, ETH-Hoenggerberg, CH-8093 Zurich, SWITZERLAND; telefax +41 1 633 1115; e-mail jansen@etp.phys.ethz.ch.
C. Klemenz and H. J. Scheel, "Flat YBa2Cu3O7-x Layers for Planar TunnelDevice Technology." To be published in Physica C. Cristallogenese, Institute of Micro- and Optoelectronics, Swiss Federal Institute of Technology, Ch. de Bellerive 34, CH-1007 Lausanne, SWITZERLAND; H. J. Scheel's telephone +41 21 693 44 52; telefax +41 21-693-47 50; e-mail hans.scheel@imo.dp.epfl.ch.
R. A. Klemm, A. M. Goldman, A. Bhattacharya, J. Buan, N. E. Israeloff, C. C. Huang, O. T. Valls, J. Z. Liu, R. N. Shelton, and U. Welp, "Comment on 'Tensor Magnetothermal Resistance in YBa2Cu3O7-x via Andreev Scattering of Quasiparticles.'" Submitted to Phys. Rev. Lett., March 13, 1996. Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov.
Hideomi Koinuma, Ryata Tsuchiya, and Masashi Kawasaki, "Crystal Engineering of Oxide Films in the Fabrication of High-Tc Josephson Tunnel Junction." To be published in Oxide Superconductors: Physics and Nanoengineering II, edited by D. Pavuna and I. Bozovic, Vol. 2697 (SPIE, Bellingham, 1996). Research Laboratory of Engineering Materials, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226, JAPAN; telephone +81 45 924 5314; telefax +81 45 924 5362; e-mail koinuma1@rlem.titech.ac.jp.
D. Kouzoudis, M. Xu, U. Balachandran, and D. K. Finnemore, "Crystal Growth at a Bi2Sr2Ca1Cu2O8/Ag Interface." To be published in the Proc. of TMS 1996 Ann. Mtg., Feb. 4-8, 1996, Anaheim, CA. Ames LaboratoryUSDOE and Department of Physics, Iowa State University, Ames, IA 500113020.
Thomas R. Lemberger, E. R. Ulm, K. M. Paget, and V. C. Matijasevic, "Fluctuation Effects in the Magnetic Penetration Depth of High-Tc Films." To be published in Oxide Superconductors: Physics and Nanoengineering II, edited by D. Pavuna and I. Bozovic, Vol. 2697 (SPIE, Bellingham, 1996). Department of Physics, Ohio State University, Columbus, OH 43210. Key words: superconductivity, YBCO, films, fluctuations, penetration depth.
Qiang Li, Y. Fukumoto, Y. Zhu, A. Suenaga, T. Kaneko, K. Sato, and Ch. Simmon, "Effect of Columnar Defects on Reversible Magnetization of Superconducting Bi2Sr2Ca2Cu3O10+d." Department of Applied Sciences, Brookhaven National Laboratory, Upton, NY 11973. 74.25.Bt; 74.60.Ec; 74.60.Ge; 74.72.Hs.
Sy-Chyi Lin, James T. Richardson, and Dan Luss, "Continuous Synthesis of YBa2Cu3O6+x by Thermal Explosion in a Rotary Kiln." To be published in Physica C, Vol. 260 (in press). Contact Dan Luss, Department of Chemical Engineering, University of Houston, Houston, TX 77204-4792; telefax (713) 743-4323. Key words: continuous, synthesis, combustion, SHS, thermal explosion, YBa2Cu3O6+x.
D. C. Ling, J. T. Chen, and L. E. Wenger, "An Investigation of Microwave-Induced dc Voltages in a YBa2Cu3O7-d Single Crystal." To be published in Phys. Rev. B. Contact J. T. Chen, Department of Physics and Astronomy, Wayne State University, Detroit, MI 48202; e-mail jtchen@hal.physics.wayne.edu. 74.25.Nf; 74.50.+r; 74.72.Bk; 74.72.-h.
Jean-Pierre Locquet, Frederic Arrouy, Erich Maechler, Michel Despont, Peter Bauer, and Erica J. Williams, "Local Electrochemical Oxidation/Reduction: First Step Towards a New Lithography?" To be published in Appl. Phys. Lett. IBM Research Division, Zurich Research Laboratory, Saeumerstrasse 4, CH-8803 Rueschikon, SWITZERLAND; telephone +41 1 724 85-79 or -77; telefax +41 1 724 0084; e-mail loc@zurich.ibm.com. 66.30.-h; 74.72.Dm; 74.62.Dh; 85.40.Hp.
A. G. Loeser, Z.-X. Shen, D. S. Dessau, D. S. Marshall, C. H. Park, P. Fournier, and A. Kapitulnik, "Excitation Gap in the Normal State of Underdoped Bi2Sr2CaCu2O8+d." Submitted to Science. Department of Applied Physics, Stanford University, Stanford, CA 94305; Z.-X. Shen's telephone (415) 725-8254; telefax (415) 725-5457 or 723-4659; e-mail shen@ee.stanford.edu.
S. E. Lofland, M. Dominguez, S. D. Tyagi, S. M. Bhagat, M. C. Robson, C. Kwon, Z. Trajanovic, I. Takeuchi, R. Ramesh, and T. Venkatesan, "Surface Resistance of Thin Perovskite Films: High Temperature Superconductors and Giant Magnetoresistance Manganites." To be published in Thin Solid Films. Department of Physics, University of Maryland, College Park, MD 20742-4111; S. M. Bhagat's telephone (301) 405-6144; telefax (301) 3149465.
J. S. Luo, N. Merchant, V. A. Maroni, M. Hash, and M Rupich, "Lead-Rich Phases in Partially Processed Ag/Bi-2223 Composite Conductors." Presented at the Symp. on High-Temperature Superconductors: Synthesis, Processing, and Large Scale Applications, Anaheim, CA, Feb. 4-8,1996; to be published in the Proc. of the TMS Ann. Mtg. Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov.
D. S. Marshall, D. S. Dessau, A. G. Loeser, C.-H. Park , A. Y. Matsuura, J. N. Eckstein, I. Bozovic, P. Fournier, A. Kapitulnik, W. E. Spicer, and Z.-X. Shen, "Unconventional Electronic Structure Evolution with Hole Doping in Bi2Sr2CaCu2O8+d: Angle-Resolved Photoemission Results." Submitted to Phys. Rev. Lett. Solid State Laboratory, McCullough Building 251, Stanford University, Stanford, CA 94305; Z.-X. Shen's telephone (415) 725-8254; telefax (415) 725-5457 or 723-4659; e-mail shen@ee.stanford.edu. 79.60.Bm, 73.20.Dx, 74.62.Dh, 74.72.Hs.
H. Mayaffre, P. Wzietek, D. Jerome, and S. Brazovskii, "Two Dimensional Vortex Melting In BEDT Organic Superconductors and NMR Relaxation Induced by Vortex Structure Defects." Submitted to Phys. Rev. Lett., Oct. 1995. Laboratoire de Physique des Solides, CNRS, Universite de Paris-Sud, 91405 Orsay, FRANCE; S. Brazovskii's e-mail brazovsk@ill.fr or brazov@lps.u-psud.fr.
A. R. Moodenbaugh, D. A. Fischer, Y. L. Wang, and Y. Fukumoto, "Superconductivity, Oxygen Content, and Hole State Density in Bi2Sr1.75Ca1.25Cu2O8.18+y (-0.09 < y <= 0) and Bi1.6Pb0.4Sr1.9Ca2Cu3Oz." Submitted to Physica C. Department of Applied Science, Brookhaven National Laboratory, Box 5000, Upton, NY 11973-5000. Key words: oxygen stoichiometry, hole concentration.
H. A. Mook, P. Dai, F. Dogan, K. Salama, G. Aeppli, and M. E. Mostoller, "Neutron Scattering Measurements on YBa2Cu3O7-d." To be published in the Proc. of the 10th Anniv. Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996 (World Sci., Singapore). Oak Ridge National Laboratory, Oak Ridge, TN 37831-6393.
Masaru Nakamura, Hiroshi Kutami, and Yuh Shiohara, "Fabrication of NdBa2Cu3O7-d Single Crystals by the Top-Seeded Solution-Growth Method in 1%, 21%, and 100% Oxygen Partial Pressure Atmosphere." 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, JAPAN; telephone +81 3 3536-5703 through -5705; telefax +81 3 3536-5714 or -5717. Key words: oxide superconductor, Nd1+xBa2-xCu3O7-d superconductor, Nd-Ba solid solution, Nd substitution, Nd ion into Ba sites.
David R. Nelson, "Ice-Like Melting of Flexible Line Crystals." Presented at the Indo-U.S. Symp. on Liquid Crystals and Supramolecular Order, Bangalore, India, Jan. 2-5, 1996; to be published in Molecular Crystals and Liquid Crystals. Lyman Laboratory of Physics, Harvard University, Cambridge, MA 02138.
A. Nittke, P. Esquinazi, W. Widder, and H. F. Braun, "Low Temperature Magnetocaloric Effects in Dy1Ba2Cu3O7-d and Y1Ba2Cu3O7-d High-Tc Single Crystals." To be published in Physica C, Vol. 260 (in press). Contact P. Esquinazi, Abt. Supraleitung und Magnetismus, Universitaet Leipzig, Linnestr. 5, D-04103 Leipzig; GERMANY; telefax +49 921 553647.
R. Noetzel, B. vom Hedt, and K. Westerholt, "Magnetic Irreversibility Lines and Critical Currents of Bi(2212) Single Crystals Doped by Fe, Ni, Co and Zn." To be published in Physica C (in press). Contact K. Westerholdt, Lehrstuhl fuer Experimentalphysik, Ruhr-Universitaet Bochum, D-44780 Bochum, GERMANY; telefax +49 234 709 4173.
M. R. Norman and A. H. MacDonald, "Absence of Persistent Magnetic Oscillations in Type-II Superconductors." Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov. 74.60.-w; 71.25.Hc; 74.25.Jb.
D. P. Norton, B. C. Chakoumakos, and J. D. Budai, "Formation and Properties of Novel Artificially-Layered Cuprate Superconductors Using Pulsed-Laser Deposition." To be published in Oxide Superconductors: Physics and Nanoengineering II, edited by D. Pavuna and I. Bozovic, Vol. 2697 (SPIE, Bellingham, 1996). Solid State Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6056. Key words: superlattices, artifically layered epitaxy, infinite layer, vortex fluctuations.
E. A. Pashitskii and V. I. Pentegov, "Anomalies of Temperature Dependence of Anisotropic Gap in High-Temperature Superconductors." To be published in JETP Lett., Vol. 63, No. 7 (in press). Contact V. I. Pentegov, Institute of Physics, NAS of Ukraine, 46 Nauki Ave., Kiev 252650, UKRAINE; e-mail pentegov@physics.kiev.ua. Key words: hightemperature superconductivity, Coulomb repulsion, gap anisotropy. 74.20.-z; 74.72.-h; 74.72.Hs.
V. Persico, V. Cataudella, F. Fontana, and P. Minnhagen, "Vortex Fluctations in BSCCO and YBCO." To be published in Physica C (in press). INFM-Dip. Scienze Fisiche, Universita' di Napoli "Federico II," Napoli I-80125, ITALY.
Hans J. Scheel, "Growth of Extremely Flat Semiconductor and Superconductor Layers by Liquid-Phase Epitaxy." Submitted as a Doctor of Engineering thesis (Faculty of Engineering, Tohoku University, Sendai, Japan, March 15, 1996). Cristallogenese, Institute of Microand Optoelectronics, Swiss Federal Institute of Technology, Ch. de Bellerive 34, CH-1007 Lausanne, SWITZERLAND; telephone +41 21 693 44 52; telefax +41 21 693 47 50.
Th. Schuster, H. Kuhn, A. Raiber, T. Abeln, F. Dausinger, Huegel, M. Klaeser, and G. Mueller-Vogt, "High-Precision Laser Cutting of HighTemperature Superconductors." To be published in Appl. Phys. Lett. Max-Planck Institut fuer Metallforschung, Institute fuer Physik, Postfach 800665, D-70506 Stuttgart, GERMANY; telephone +49 711 6 89 1801; telefax +49 711 6 89 1010.
S. Sengupta, Donglu Shi, J. S. Luo, A. Buzdin, V. Gorin, V. R. Todt, C. Varanasi, and P. J. McGinn, "Effect of Extremely Fine Y2BaCuO5 Precipitates on the Critical Current Density of Melt-Processed YBa2Cu3Ox." Submitted to Phys. Rev. B, March 1996. Superconductive Components, Inc., 1145 Chesapeake Avenue, Columbus, OH 43212.
Donglu Shi, "Can We Achieve High In-Field Jc at 77 K in Bi-Sr-Ca-Cu-O?" Submitted to J. Mater. Res., March 1996. Department of Materials Science and Engineering, University of Cincinnati, Cincinnati, OH 452210012.
Lei Shi, Takuya Ohba, Toru Hara, Masahiko Tanaka, and Yuheng Zhang, "Diffuse Scattering Study of Bi2Sr2CaCu2Od Crystals." Submitted to the XVII Congress and General Assembly of the Int. Union of Crystallography, Seattle, WA, Aug. 17, 1996. Department of Materials Science and Engineering, Teikyo University, Toyosatodai 1-1, Utsunomiya 320, JAPAN; e-mail shil@koala.mse.teikyo-u.ac.jp. Key words: diffuse scattering, Bi2Sr2CaCu2Od superconductor, single crystal.
U. Staub, L. Soderholm, S. Skanthakumar, S. Rosenkranz, C. Ritter, and W. Kagunja, "Tb Spin Correlations in Pb2Sr2Tb0.5Ca0.5Cu3O8." To be published in Europhys. Lett. Swiss Light Source Project, Paul Scherrer Institut, CH-5232 Villigen PSI, SWITZERLAND; telephone +41 56 310 41 18; telefax +41 56 310 29 39; e-mail urs.staub@psi.ch. 71.70.Ch; 75.40.-s; 74.72.Jt.
Francesco Tafuri, Alessandro Di Chiara, Fabrizio Fontana, Filomena Lombardi, and Giuseppe Peluso, "Quasiparticle Transport in Microjunctions Employing Normal Metal/Superconductor Interfaces in Presence of a Magnetic Field." To be published in Oxide Superconductors: Physics and Nanoengineering II, edited by D. Pavuna and I. Bozovic, Vol. 2697 (SPIE, Bellingham, 1996). Dip. di Ingegneria, Seconda Universita degli Studi di Napoli, Via Roma 29, 81031 Aversa (Ce), ITALY. Key words: proximity effect, point contact and tunneling spectroscopy, conductance zero-bias anomalies.
Masato Tazawa, "New Possibility to Study High Reflectance Materials in FIR: Application to High Tc Superconductors." Submitted as a Ph.D. thesis (Universite Henri Poincare, Nov. 10, 1995). Laboratoire Infrarouge Lointain, Universite Henri Poincare, Nancy 1, F-54506 Vandoeuvre les Nancy Cedex, FRANCE.
M. H. Theunissen, E. Van der Drift, and P. H. Kes, "Size-Effects in Flow of Flux-Line Solids and Liquids." Kamerlingh Onnes Laboratorium, Leiden University, 2300 RA Leiden, THE NETHERLANDS.
A. M. Thompson and M. A. Moore, "Instabilities in the Flux Line Lattice of Anisotropic Superconductors." Submitted to Phys. Rev. B. Theory Group, Department of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UNITED KINGDOM; telephone +44 161 275 4188; telefax +44 161 275 4218; e-mail amt@a13.ph.man.ac.uk.
David J. Thompson, L. E. Wenger, and J. T. Chen, "Inducing the Paramagnetic Meissner Effect in Nb Disks by Surface Ion Implantation." Submitted to Phys. Rev. B. Department of Physics and Astronomy, Wayne State University, Detroit, MI 48202; e-mail thompson@hal.physics.wayne.edu. 74.60.Ec; 74.25.Ha; 74.60.Ge; 74.62.Bf.
Hisayo Tomita, Tomoko Goto, and Kiyoshisa Takahashi, "Solution Spinning of High-Tc Oxide Superconductor: Part VII -- The Effect of Polyvinyl Alcohol Spinning Medium on the Sintering of YBa2Cu3Ox Superconducting Filaments." To be published in Supercond. Sci. & Technol., Vol. 9 (in press). Contact Tomoko Goto, Department of Materials Science & Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466, JAPAN; telephone +81 52 735 5265; telefax +81 52 735 5294; e-mail zwgoto@mse.nitech.ac.jp.
Hisayo Tomita, Tomoko Goto, Kazuo Watanabe, Satoshi Awaji, and Kiyohisa Takahashi, "The Field Dependence of Jc for the Y123 Filament Spun from Various Spinning Dope." Contact Tomoko Goto, Department of Materials Science & Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466, JAPAN; telephone +81 52 735 5265; telefax +81 52 735 5294; e-mail zwgoto@mse.nitech.ac.jp.
Hisayo Tomita, Takashi Omori, Tomoko Goto, and Kiyoshisa Takahashi, "Solution Spinning of High Tc Oxide Superconducting Filament: Part VIII -- The Effect of Degree of Saponification of Poly (Vinyl Alcohol) on the Critical Current Density of Y1Ba2Cu3Ox Superconducting Filament." Submitted to J. Mater. Sci. Contact Tomoko Goto, Department of Materials Science & Engineering, Nagoya Institute of Technology, Gokisocho, Showa-ku, Nagoya 466, JAPAN; telephone +81 52 735 5265; telefax +81 52 735 5294; e-mail zwgoto@mse.nitech.ac.jp.
R. Weinstein, J. Liu, Y. Ren, R.-P. Sawh, D. Parks, C. Foster, and V. Obot, "Very High Trapped Fields: Cracking, Creep, and Pinning Centers." Presented at the 10th Anniv. Workshop on Physics, Materials, and Applications, Houston, TX, March 12-16, 1996. Institute for Beam Particle Dynamics, 632 Science Research Building, University of Houston, Houston, TX 77204-5506; telephone (713) 743-3600; telefax (713) 7474526.
Stuart A. Wolf, Vladimir Z. Kresin, and Yu. N. Ovchinnikov, "Pair Breaking and 'Intrinsic' Tc." To be published in Oxide Superconductors: Physics and Nanoengineering II, edited by D. Pavuna and I. Bozovic, Vol. 2697 (SPIE, Bellingham, 1996). Naval Research Laboratory, Washington, DC 20375-5000. Key words: cuprates, pair breaking, magnetic impurities, gaplessness, pressure effects, "intrinsic" Tc.
Th. Wolf, H. Kuepfer, and H. Wuehl, "Irreversibility Fields Above 13 T at 77 K in NdBa2Cu3O7-d." To be presented at the Eighth Int. Workshop on Critical Currents in Supercond., (8th IWCC), Kitakyushu, Japan, May 27-29,1996. Contact H. Kuepfer, Forschungszentrum Karlsruhe, Institut fuer Technische Physik, Postfach 3640, D-76021 Karlsruhe, GERMANY; telephone +49 7247 82 4656; telefax +49 7247 82 2849.
Ch. Wolters, K. M. Amm, Y. R. Sun, and J. Schwartz, "Synthesis of (Hg,Re)Ba2Can-1CunOy Superconductors." Submitted to Physica C. Magnet Development and Technology Group, National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Drive, Tallahassee, FL 32306-4005; telephone (904) 644-6788; telefax (904) 6440867; e-mail wolters@magnet.fsu.edu. Key words: HgBaCaCuO, rhenium, stability, growth, melt.
Chien-Jang Wu and Tseung-Yuen Tseng, "ac Response of the Vortex Liquid in the High-Tc Superconducting Cylinder." To be published in Physica C, Vol. 333 (in press). Department of Electronics Engineering and Institute of Electronics, National Chiao-Tung University, Hsinchu, Taiwan, REPUBLIC OF CHINA. Key words: mixed state, penetration depth, type-II superconductors, flux lattice.
N. J. Wu, D. Liu, Y. S. Chen, H. Lin, A. R. Zomorrodian, and A. Ignatiev, "Infrared Photocurrent Study of PZT/YBCO and PMSZT/YBCO Heterostructures." Preprint #96:016; submitted to the Proc. of the 10th Ann. Int. Aerospace Symp. (SPIE 96), Orlando, FL, April 8-12, 1996. Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu. Key words: pyroelectrics, ferroelectrics, photocurrent, infrared, laser ablation, thin film.
X. S. Wu, H. M. Shao, S. S. Jiang, C. Gou, D. F. Chen, D. W. Wang, and Z. H. Wu, "Synthesis and Neutron Powder Diffraction Studies of the Superconductor HgBa2Ca2Cu3O8+d by Pb Substitution." To be published in Physica C (in press). National Laboratory of Solid State Microstructures and Center for Advanced Studies in Science and Technology of Microstructures, Nanjing University, Nanjing 210093, PEOPLE'S REPUBLIC OF CHINA.
M. Wurlitzer, M. Lorenz, K. Zimmer, and P. Esquinazi, "ac Susceptibility of Structured YBa2Cu3O7 Thin Films in Transverse Magnetic ac Fields." Department of Superconductivity and Magnetism, Universitaet Leipzig, Linnestrasse 5, D-04103 Leipzig, GERMANY. 74.60.Ge; 74.72.Bk; 74.76.Bz.
M. Wurlitzer, F. Mrowka, P. Esquinazi, K. Rogacki, B. Dabrowski, E. Zeldov, T. Tamegai, and S. Ooi, "Global ac Susceptibility of Low Pinning High-Tc Crystals Near Tc." Department of Superconductivity and Magnetism, Universitaet Leipzig, Linnestrasse 5, D-04103 Leipzig, GERMANY. 74.60.Ge; 74.72.Bk; 74.72.Hs.
U. Yaron, P. L. Gammel, A. P. Ramirez, D. A. Huse, D. J. Bishop, A. I. Goldman, C. Stassis, P. C. Canfield, K. Mortensen, and M. R. Eskildsen, "Observation of a Square Flux-Line Lattice in the Magnetic Superconductor ErNi2B2C." Submitted to Nature, March 21, 1996. Room 1D-217, Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07974; telephone (908) 582-4672; telefax (908) 582-3260.
June 11 - 13, 1996: International Conference on Advanced Materials and Devices (ICAMD'96), Phoenix Park, Korea. Satellite to the Inauguration Conference of the Asia-Pacific Center for Theoretical Physics (APCTP) to be held June 4 -10, 1996. Conference will provide an interdisciplinary forum for discussions on recent experimental and theoretical results in physics, chemistry, materials science, and engineering of advanced materials. Contributions to theory, synthesis, structure, and properties in the following fields are anticipated: high-Tc superconductors, organic superconductors, photonic materials, nanostructures, advanced magnetic materials, and applications and devices. Plenary lectures as well as invited and contributed papers. For further information, contact Prof. Yung Woo Park, Program Committee Chair of ICAMD'96, Department of Physics, Seoul National University, Seoul 151-742, Korea; telephone +82 2 880-6607; telefax +82 2 873-7037; e-mail ywpark@alliant.snu.ac.kr.
June 13 - 14, 1996: Superconductivity -- Fulfilling Tomorrow's Global Needs, First Symposium of the Educational Institute for Superconductivity (EIS'96), Washington, DC. Purpose is to advance the science and technology of superconductivity and educational applications by providing an educational forum in which representatives from industry, laboratories, universities, and government agencies can exchange ideas and information critical for the development and commercialization of superconductivity applications. The superconductivity industry, its sponsoring agencies, and R&D laboratories will present papers and exhibits focusing on current and future plans, applications, and new technologies. Will include plenary sessions of invited papers on topics related to the development and marketing of products based on low- and high-temperature superconductivity, as well as observations and prospects in the marketplace. Parallel sessions to be held in the following areas: electric power applications, accelerator and fusion applications, electronic applications, and others. For further information, contact Pam Patterson, Conference Manager, Educational Institute for Superconductivity, P.O. Box 178441, San Diego, CA 92177; telephone (619) 490-0164; telefax (619) 490-0138.
*July 22 - 26, 1996: Conference on Quantum Coherence in Strongly Correlated Fermion Systems, Scuola Normale Superiore, Pisa, Italy. Satellite of XXI International Conference on Low Temperature Physics (LT21), Prague, August 8-14, 1996. Sponsored by the INFM (Istituto Nazionale di Fisica della Materia). Purpose of the conference is to bring together scientists working on different but related topics of condensed-matter and statistical physics to allow for a "productive cross-fertilization" Topics will include disordered systems (Anderson localization and electron-electron interaction, spin-glass, and neural network); strongly correlated electron systems (metal-insulator transition, non-Fermi-liquid metallic phase, and superconductivity); quantum chaos and mesoscopic systems; renormalization group in fermion systems; and exact results and relation with field theory. Participation restricted to eighty persons. Deadline for participation request, April 30, 1996. Request for participation and proposed contributions (including fax number and e-mail of the applicant) should be sent to M. Grilli, Universita' di Roma "La Sapienza," Piazza A. Moro, 2, I-00185 Rome, Italy; telephone +39-6-4991-4341; telefax +39-64957697; e-mail grilli@roma1.infn.it.
*August 4 - 7, 1996: Weak Superconductivity Symposium, Smolenice, Slovak Republic. Satellite to the LT21 Conference at Prague, Czech Republic, Aug. 8 - 14, 1996. Organized by the Institute of Electrical Engineering, Slovak Academy of Sciences, Bratislava, and the Slovak Republic in collaboration with the Institut fuer Festkoerperphysik of Friedrich-Schiller-Universitaet, Jena, Germany. Purpose is the exchange of the newest results in the field of low- and high-temperature weak superconductivity. The symposium continues in the tradition of meetings on selected aspects of weak superconductivity since 1977. The main subjects are: Josephson effects and tunneling in LTS and HTS weak-link structures; intrinsic properties of HTS (stack junctions, multilayers); Josephson effects in mesoscopic systems; proximity junctions; static and dynamic properties of weak-link arrays; transport phenomena in thin films and weak links; SQUIDs and their applications; cryoelectronic devices; and materials for LTS and HTS and their properties. All contributions to be published as part of the NATO ASI Series or in a volume of J. Low Temp. Phys. Symposium language is English. Contact the Organizing Committee WSS96, Institute of Electrical Engineering SAS, Dubravska cesta 9, SK-842 39 Bratislava, Slovak Republic; telephone +42 7-378-2139 or -2670; telefax +42 7-375816; e-mail wss96@savba.sk. Or contact the Organizing Committee WSS96, Institut fuer Festkoerperphysik, Friedrich-Schiller-Universitaet Jena, Helmholtzweg 5, D-07743 Jena, Germany; telephone +49 3641 6 35685; telefax +49 3641 6 35738; e-mail wss96@ifk.uni-jena.de. Information about the symposium also available at the WWW site http://www.savba.sk/sav/wss96/intro.html.
*Aug. 5 - 8, 1996: Workshop on Fluctuation Phenomena in HTSC, International Centre for Theoretical Physics, Trieste, Italy. Three main fields of fluctuation phenomena in superconductors will be discussed: order parameter fluctuations above Tc, phase fluctuations in the vicinity of Kosterlitz-Thouless transitions, and quantum and thermal fluctuations of vortices in HTSC. Topics to be covered include transport properties in the ab plane and along the c axis, effect of fluctuations on the Knight shift and the NMR relaxation rate, calculations of superconducting fluctuations beyond a BCS approach, effect of fluctuations on tunneling phenomena, specific role of the density of states fluctuation in HTSC, fluctuation effect as a probe for the type of symmetry of the order parameter, effect of magnetic field on fluctuation phenomena for static and transport properties, and others. Workshop open to all researchers from countries that are members of UN, EEAC, IAEA, NATO, or UNESCO. No registration fee. "Request for Participation" form obtainable via e-mail from smr860@ictp.trieste.it and typing "get index" on subject line or via gopher server at gopher.ictp.trieste.it. Forms should be mailed to Adriatico Research Conferences, International Centre for Theoretical Physics, P.O. Box 586, I-34100 Trieste, Italy.
*Aug. 25 - 30, 1996: The 1996 Applied Superconductivity Conference, Pittsburgh Convention Center, Pittsburgh, PA. Hosted by Westinghouse Science and Technology Center. Major areas: superconducting materials for a wide range of applications, superconducting electronics, and large-scale applications. Celebration luncheon commemorating the 10th anniversary of the discovery of HTS materials will feature distinguished speakers in the field. The 1996 meeting will use both oral and poster formats for invited presentations. For information, contact William Shoemaker, Conference Manager, AHI Conference Management, Hudsons Cross Roads, Selbyville, DE 19975; telephone (800) 788-7077; telefax (302) 436-1911; e-mail convene@ aol.com.
*Sept. 16 - 20, 1996: International Conference on Substrate Crystals and HTSC Thin Films, Jaszowiec, Poland. Aim is to provide an interdisciplinary forum for scientists amd engineers for an exchange of investigation results and and experience in the growth of substrate single crystals and thin films of HTSC. The following topics will be discussed: (1) substrate single crystals -- oxide crystals of perovskite- and pseudo-perovskite-type structure, crystal growth, properties of crystals; (2) interface -- misfit between film and substrate, lattice constants and distances of ions, orientation, defect ordering, surface preparation, interdiffusion, structure compatibility, and thermal expansion; (3) thin films of HTSC -- surface reconstruction, in-situ observations of thin-film growth, physical and chemical properties of films related to substrate crystal, network of defects, and epitaxial tension. Invited lectures, contributed oral and poster sessions. Conference language is English. For information contact M. Berkowski, Secretary, ICSC--F'96, Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Poland; telephone +48 22 437001 ext. 344; telefax +48 22 430926; e-mail scf96@ifpan.edu.pl.
*Nov. 12 - 15, 1996: 41st Annual Conference on Magnetism & Magnetic Materials, Atlanta Hilton Towers, Atlanta, GA. Sponsored jointly by the American Institute of Physics and the Magnetics Society of the IEEE. Call for papers. Conference will include all areas of basic and applied science and technology related to magnetism. Technical subject categories will include fundamental properties and cooperative phenomena, transport properties, computational magnetics and imaging, soft magnetic materials and applications, hard magnetic materials and applications, artificially structured materials, other magnetic materials, magnetic recording, applications, and interdisciplinary topics. Abstract deadline, May 29, 1996. Proceedings to be published in a special issue of J. Appl. Phys. Invited and contributed papers as well as an exhibition of services, equipment, and materials. For further information, contact Diane Suiters, Conference Coordinator, 655-15th St. N.W., Suite 300, Washington, DC 20005; telephone (202) 6395088; telefax (202) 347-6109; e-mail magnetism@mcimail.com. (Preliminary program and general Conference information available after Sept. 15, 1996, at the URL address http://www.aip.org/edops/mmm96prog.html.)
*March 6 - 8, 1997: International Workshop on Critical Currents in Superconductors for Practical Applications (SPA '97), Xi'an, China. Satellite conference to the Fifth International Conference on Materials and Mechanisms of Superconductivity (M^2S-HTSC-V) at Beijing. SPA'97 will concentrate on improvement of practical superconducting materials and their applications. Main topics are synthesis and processing of practical materials; properties of high-Tc tapes, cables, coils, and bulk materials; critical currents and microstructures; flux dynamics and pinning mechanisms; applications of high-Tc and low-Tc materials; processing and physical properties of high-Tc films; and applications of high-Tc films. Conference language is English. Abstract deadline, December 1, 1996; authors notified of acceptance by January 1, 1997. For information, contact P. X. Zhang, Conference Secretary, SPA '97, Northwest Institute for Nonferrous Metal Research, P.O. Box 51, Xi'an, Shaanxi 710016, People's Republic of China; telephone +86 29 6231079; telefax +86 29 6231103; e-mail pxzhang@xjtu.edu.cn.
Information
The NIST High-Temperature Superconductors Database for PCs provides materials researchers in industry, federal laboratories, and universities with rapid access to carefully evaluated information on 24 thermal, mechanical, and superconducting properties for oxide superconductors. Standard Reference Database 62 covers approximately 130 series of compounds derived from the YBCO, Bi-Sr-Ca-Cu-O, Tl-Sr-CaCu-O, and La-Cu-O chemical families, along with numerous other variants of the cuprate and bismate materials known to have superconducting phases. Materials are described by specification, and characterization information includes processing details and chemical conditions. Data from about 400 papers published between 1987-1993 are presented. Price is $265 for SRD 62 PC Version1.0. Contact Standard Reference Data Program, Rm. 113, Bldg. 820, NIST Gaithersburg, MD 20899-0001; telephone (301) 975-2208; telefax (301) 926-0416; e-mail srdata@enh.nist.gov.
Products and Services
New Web site: American Magnetics Inc. (AMI) announces the availability of product and services information via the World Wide Web accessible at http://www.usit.net/ami. Includes comprehensive information on AMI's standard product lines as well as customer services and technical support sections. Site also includes sections detailing AMI's offerings in the areas of superconducting magnet systems and supporting mechanical equipment, cryogenic instrumentation, and Mossbauer spectroscopy. Online application guides and downloadable versions of operational manuals and software provided. The company welcomes comments and suggestions for future enhancements. Contact American Magnetics, Inc., P.O. Box 2509, 112 Flint Road, Oak Ridge, TN 37831-2509; telephone (423) 4821056; telefax (423) 482-5472; e-mail amagi@usit.net.
Automated sample rotation is now available as an option in Quantum Design's Physical Property Measurement System (PPMS). Research areas that can benefit from this horizontal sample rotator include anisotropic resistivity measurements and anisotropic magnetoresistance. Rotator allows for automated measurement of electro-transport properties of a sample while controlling the orientation between the sample and an applied magnetic field. Angular position of the rotator controlled by a precision stepper motor that provides a minimum angular increment of 0.05 degree, and allows sample to rotate through more than one full revolution to provide a full range of motion. Designed for use with either the integrated four-channel resistivity option or the new ac Transport Measurement System. Available for performing dc and ac resistivity, Hall effect, critical current, and I-V measurements. For more information, contact Chris Gardner, Quantum Design, 11578 Sorrento Valley Road, San Diego, CA 92121-1311; telephone (619) 481-4400; telefax (619) 481-7410; e-mail info@quandsn.com.
Positions available: Postdoctoral positions are available in the Superconducting Technology Program at Oak Ridge National Laboratory for persons with experience in growth and characterization of thin- and thick-oxide films. Expertise in the following areas is of interest: physical vapor-deposition methods including e-beam evaporation, sputtering, and pulsed-laser ablation; wet chemical methods for thinand thick-film processing, including sol-gel and metal-organic decomposition; and microstructural characterization by XRD, SEM, and TEM. For information contact D. M. Kroeger, Metallurgy & Ceramics Dept., Oak Ridge National Lab., P.O. Box 2008, Oak Ridge, TN 37831-6115; telephone (423) 574-5155; telefax (423) 574-7659; e-mail okg@ornl.gov.
Ph.D. student being sought to work on research project of the Swiss National Foundation. Area of work will include epitaxy problems and crystal-growth technology of high-Tc superconductors, and structural and chemical characterization. Project seeks person with multidisciplinary interests, good intuition for complex multiparameter processes, experimental skills, and special interest in science and technology of crystal growth. Duration of project about 36 months. Salary: 3,000 sFr/mo. Starting date: as soon as possible. Send application to Hans J. Scheel, Cristallogenese - IMO, Ch. de Bellerive 34, CH-1007 Lausanne, Switzerland; telephone +41 21-693-4452; telefax +41 21 693-4750; e-mail hans.scheel@imo.dp.epfl.ch.
High-Tc Update is available on World Wide Web (WWW) (see URL on the newsletter header. In addition, High-Tc Update is available electronically as an ASCII file or as coded Word files from an anonymous ftp site. To download electronic versions of the newsletter, please follow the procedure below:
ftp hightc.ameslab.gov USERNAME: anonymous PASSWORD: [your username] cd pub
get filename.ext
The file names are, for example, 96apr15.rtf (for RTF version), 96apr15.hqx (for BINHEX version), and 96apr15.em.txt (for ASCII version). Coded Word files are available at this site from Nov. 15, 1993 issue; ASCII files are available from Jan. 1992 to the present issue.
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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. Telex: 269266. E-mail: MITRA@AMESLAB.GOV or MITRA@IASTATE.EDU. Project Director/Editor: Sreeparna Mitra Science Editor: John R. Clem High-Tc Update, Vol. 10, #8, April 15, 1996.