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Stripes
A model has been developed by C. C. Tsuei et al. (IBM, Yorktown) in which quantum level effects in cuprate superconductors may explain the observed normal-state pseudogap in the excitation spectrum. They focus on the fact that the stripe phase and the pseudogap in cuprate superconductors occur in the same doping range. They propose a model based on charge confinement in self-organized nanoscale stripe fragments to understand various generic features of the normal-state energy gap including the magnitude of the gap, its anticorrelation with Tc, and the observed d-wave symmetry. Based on STM and neutron scattering data, they envisage holes self-organizing into nanoscale boxes with an average dimension of 1.5 x 1.3 x 10 nm separated by insulating antiferromagnetic domains. The resulting quantum level spacings and parity effect arising from charge confinement in these nano-boxes leads to reasonable energy scales, doping dependence of the pseudogap onset temperature (T*), and its anticorrelation with the superconducting transition temperature (Tc). They calculate a pseudogap excitation energy (E_G) that ranges from about 60 meV at low doping to about 10 meV for 0.2 holes per CuO2. To achieve a coherent superconducting state, there must be coupling between the boxes by tunneling or a proximity effect. The model may provide a basis for understanding other anomalous normal-state properties of the cuprates.
The dynamical behavior of stripe phase materials in the presence of disorder and lattice potentials has been studied by N. Hasselmann (UC- Riverside) et al. Perturbative renormalization group techniques are used to study fluctuations in transverse stripes. Three different phases are found depending on the stripe density, the ratio of the kinetic to confining energy, the strength of the disorder, and the lattice strength. One phase is pinned by disorder, one by the lattice, and one phase is gaussian.
A preprint by R. S. Markiewicz (Northeastern) suggests that recent experiments provide evidence for charge density modulations along the stripes in stripe-phase materials. At the 1/8 doping, there is a crossover from wide magnetic stripes at low doping to wide hole-doped stripes at high hole doping. The crossover is reflected in the doping dependence of the spin gap. If the hole-doped stripes are wide near optimal doping, this will have an impact on modeling the nature and origin of superconductivity in these materials.
Thermal conductivity measurements are reported by J. L. Cohn (U. Miami) et al. over a broad range of doping in YBCO and Hg cuprates. The authors find that small domains of holes develop at hole concentrations near 1/8. The data imply a mechanism for localization that is intrinsic to the CuO2 planes and that is enhanced by oxygen-vacancy clusters.
Vortices
A paper by A. E. Koshelev (Argonne) et al. demonstrates how the Josephson plasma resonance can be used to probe the strength of the Josephson coupling between layers along the c-axis over a wide range of the vortex phase diagram. They derive a relation between the field dependent Josephson coupling energy and the density correlation function of the vortex liquid. This relation provides an opportunity to extract the density correlation function of pancake vortices from the dependence of the plasma resonance. The dependence of the plasma frequency on the magnetic field parallel to the a-b plane (B_x) under the conditions of a fixed component of magnetic field along the c-axis (B_z) contains the full structural information about the vortex liquid at that B_z and temperature.
The effect of bulk pinning and surface barriers on vortex motion in the vortex liquid state of Bi(2212) single crystals has been studied by A. Mazilu (U. Illinois, Chicago) et al. Using a Corbino disk geometry, where vortices move in circular paths without crossing the sample edge, results without surface pinning may be obtained and compared to four probe results with surface pinning. They find the same temperature and magnetic-field dependence for the electrical resistivity in the vortex liquid state, the same activation energies for vortex motion, and the same irreversibility lines. In these crystals, flux motion in the liquid state is governed by bulk effects.
A manuscript by T. Klein (Grenoble) et al. reports a detailed characterization of the vortex glass transition in K-Ba-Bi-O. The vortex-glass correlation length reaches several micrometers in the vicinity of the transition showing that vortices are correlated over more than 200 times the vortex lattice spacing. The characteristic exponents are field independent and do not depend on the relative orientation of the magnetic field and current density.
Point defect and correlated disorder pinning in untwinned YBCO have been studied by W. K. Kwok et al. (Argonne) using transport measurements. The first-order vortex melting line, which terminates at a critical point in high magnetic fields, is strongly dependent on point disorder induced by proton irradiation. Increasing point disorder can shift the critical point down along the first-order vortex melting line. For columnar defects, the first order vortex melting line is suppressed and replaced by a continuous transition. Anisotropic pinning from columnar defects induced by uranium heavy ions can extend up to the superconducting transition temperature, T_[co], suggesting that even in the superconducting fluctuation regime, these defects are capable of pinning the vortex liquid.
A paper by A. A. Zhukov (Moscow State U.) et al. reports a narrow dip in the angular dependence of the irreversible magnetic moment in YBCO single crystals with columnar defects. Using the anisotropic critical state model, they show that the anomaly arises from a sharp increase of the critical current density parallel to the field rotation plane. A quantitative prediction of this model is that at large angles, the ratio of the parallel and perpendicular current densities approach the sample aspect ratio.
Theory
The problem of N nonmagnetic impurities in the staggered flux phase of the Heisenberg model has been solved by C. Pepin et al. (MIT). They assume that this is a good mean field approximation for the spin-gap phase of the cuprates. The density of states is evaluated exactly in the unitary scattering limit and is proportional to 1/[(omega)ln^2((omega)/D)] in analogy with the 1D case of doped spin- Peirels and two-leg ladder compounds. The model predicts low energy fluctuations in neutron scattering.
A paper by D. K. Morr et al. (U. Illinois, Urbana-Champaign) pursues the consequences of a theory in which the resonance peak observed in inelastic neutron-scattering experiments on underdoped and optimally doped YBCO arises from a spin-wave excitation. In the normal state, this mode is heavily damped and is thus almost not observable, but becomes visible in the superconducting state due to a drastic decrease in spin damping. They show that a spin-fermion model correctly describes the temperature dependence of the peak position for YBCO as well as the doping dependence of the peak position and of the integrated intensity. They also explain why no peak is observed in La(214).
Mean-field and exact-diagonalization studies on the quasiparticle excitation of an SO(5) symmetric two-leg-ladder system is reported by S.-P. Hong et al. (Pohang U.). The energy gap in the quasiparticle excitation spectrum is caused by the formation of rung singlet states. They find that shadow peaks can occur above the Fermi surface with antiferromagnetic electron correlation involving only rungs in the spin ladder.
A paper by N. A. Mortensen (Tech. U. Denmark) et al. reports the angle dependence of Andreev scattering at a semiconductor-superconductor interface. They generalize the Blonder-Tinkham-Klapwijk one-dimensional model and find that an increase in the momentum parallel to the interface leads to a suppression of the probability of Andreev scattering. They find that the BTK model overestimates the barrier strength for two- and three-dimensional interfaces.
Nonlinear transport through NS junctions due to imperfect Andreev scattering has been studied by G. B. Lesovik (Chernogolovka) et al. As the effective Fermi energy drops below the gap energy, a conducting band with a width twice the Fermi energy is formed. Depending on the mode of operation, the conduction band can be further squeezed leading to various non-linear effects in the current-voltage characteristics such as current saturation, bistability, and hysteresis.
An attractive nearest neighbor Hubbard model, which is the simplest model that allows s-wave, d-wave, or a mixed pairing has been examined by J. F. Annett et al. (U. Bristol). The phase diagram includes regions of both extended s-wave superconductivity and d-wave pairing. The p- wave pairing is never stable. Near the s- to d-wave crossover, they find that the two phases are separated by two second-order phase transitions with an intermediate s+-id phase.
A paper by M. Vojta et al. (Florida State) discusses the possibility of superconductivity in a doped triangular antiferromagnet. Using the Bethe-Salpeter equation, they show that the exchange of RPA paramagnons on a triangular lattice Hubbard model leads to strong pairing correlation near half-filling. Both weak-coupling and strong-coupling approaches suggest that the system presents a pairing instability in the s-wave triplet channel, while small deviations from the regular triangular arrangement stabilize a d-wave singlet superconducting state similar to the square lattice.
The theory of the ac Josephson effect in superconducting d-wave junctions has been studied by M. Hurd et al. (Goeteborg). The presence of zero-energy mid-gap states at the interfaces influence the current- voltage curves because they open new channels for current flow. There are current peaks at finite voltage leading to negative differential conductance.
A paper by C. Buhler et al. (Florida State) reports the study of spin and charge fluctuations in the U-t-t' model in order to explain features of neutron scattering and ARPES data. Good agreement is found between the computed values and the data for both LSCO and YBCO. It is also shown that using a more negative t'/t ratio of the hopping energies will induce short-range magnetic incommensuration along the diagonal direction in the Brillouin zone, in qualitative disagreement with experiment.
Susceptibility scaling and vertex corrections for a nested Fermi surface relevant to d-wave superconductors, organic metals, and chromium have been studied by A. Virosztek et al. (U. Virginia). They show that self- energy and vertex corrections preserve the scaling features of susceptibility to leading order in the Hubbard on-site Coulomb repulsion, U. Analytic results for static susceptibility show how self- energy and vertex terms modify the traditional RPA results for spin- density-wave instability and suppress the charge susceptibility.
The effects of Van Hove singularities on the thermal properties of high- temperature superconductors is reported by S. Dorbolo et al. (U. Liege). Specific heat, thermal conductivity and thermal diffusivity are calculated within a phenomenological model that includes both s-wave and d-wave gap symmetries. A relation between the doping level and the oxygenation rate is found.
Electromagnetic Properties
A paper by H. L. Liu (U. Illinois) et al. reports the c-axis polarized electronic Ramam scattering of BSCCO single crystals. In the normal state, a resonant electronic continuum extends to 1.5 eV and gains significant intensity as the incoming photon energy increases. In the superconducting state, a coherence 2(Delta) peak appears around 50 meV, with a suppression of the scattering intensity at frequencies below the peak position. The existence of this peak suggests that three dimensional superconducting coherence is present in overdoped Bi(2212) at low temperatures. The peak energy, which is higher that that seen with in-plane polarizations, signifies distinctly different dynamics of quasiparticle excitations created with out-of-plane polarization relative to the in-plane case.
>From the optical response of Ba-K-Bi-O, H. J. Kaufmann (Cambridge) et al. observe that the analysis of far-infrared data using Migdal- Eliashberg theory is not consistent with standard electron-phonon coupling. They find that the data can be understood with a weak electron-phonon coupling plus an unspecified high energy excition near 0.4 eV.
A manuscript by F. Raffa (U. Zurich) et al. reports the isotope dependence of the spin gap in Y(124) as determined by Cu NQR relaxation. Measurements of the change in spin gap temperature, T*, and the superconducting transition temperature, Tc, with the exchange of [16]^O by [18]^O gives a spin gap isotope effect coefficient of 0.061 compared to the superconducting Tc isotope coefficient of 0.056. Because these are the same within error bars, it suggests a common origin for the superconducting gap and the spin gap.
Microwave properties of YBCO thin films in the linear and nonlinear regime in dc magnetic field are reported by M. I. Tsindlekht (Hebrew University) et al. Measurements show that the nonlinear contribution to the microwave response from the microwave currents and the contribution from the moderate dc magnetic field are additive and almost do not influence one another. This means that the nonlinear microwave performance of YBCO thin films is not seriously affected by a dc magnetic field. It appears that the most important source of nonlinearity is from vortices created by the microwave field, probably in weak links.
Materials
>From isothermal four-point electrical resistivity measurement, S. Kittelberger et al. (Tuebingen) have determined the chemical diffusion coefficients for in- and out-diffusion of oxygen in epitaxial c-axis oriented films of YBCO from 500 K to 600 K. At constant oxygen pressure, they observe the temporal changes in resistivity, following small steps upward or downward in temperature. At 600 K, for in- and out-diffusion of oxygen, they found about the same diffusion constant of 2 x 10^[-14] cm^2/s. The temperature dependence of the diffusion constant could be fitted by an Arrhenius law yielding an activation energy of 1.1 eV.
A paper by H. Zheng et al. (Argonne) reports the growth and physical properties of melt-textured mixtures of Y(123) and Gd(123). Samples were grown in air with a top seeding method that employs Nd(123) seeds. The green phase particles are small and well dispersed even without the addition of Pt. For samples with Tc near 91 K, the critical current densities are in the range of 10,000 A/cm^2 at 77 K and 2 Tesla. The irreversibility field at 77 K is about 6 Tesla.
A paper by J.-P. Locquet (IBM Zurich) et al. reports large increases in the transition temperature of La-214 with the uniaxial strains that arise from the epitaxial growth of a few unit cells of the superconductor on various substrates. With a strontium titanate substrate, they report tensile strains, more semiconducting-like resistivity data, and a lower transition temperature. With a strontium- lanthanum aluminate substrate, they report compressive strains, lower resistance metallic behavior, and transition temperatures as high as 49 K.
A manuscript by M. El Massalami (Rio de Janeiro) et al. reports superconductivity in the intermediate valence CeNi2B2C, the first Ce- based intermediate valence superconductor. The Tc is 0.1 K; the ratio of the jump in specific heat to gamma Tc is 1.2; and the energy gap 2(Delta) is about 0.35 K. These values are close to a weak coupling BCS superconductor.
Magnetization and magnetoresistivity measurements on Ba-Cu-O2/Ca-Cu-O2 superlattices grown by pulsed laser deposition by G. Balestrino (U. Rome) et al. show that these materials have a metallic normal-state resistivity and a transition temperature of about 74 K. The hole carrier concentration derived from Hall measurements are as high as 0.55 carriers/unit cell. Critical current densities and flux creep measurements are comparable to results in YBCO.
Copper NQR and bromine XAFS have been used by D. M. Potrepka et al. (U. Connecticut) to study the local atomic environment in well-characterized samples of oxygen deficient YBCO. From NQR they conclude that after bromination at 260^oC, oxygen has repopulated the chain sites. From the XAFS, it is concluded that Br does not enter the YBCO lattice, but rather precipitates out as small nanoscale particles of BaBr2. The results provide clear evidence of the role of Br in the reoxygenation of the YBCO structure and an explanation for the partial restoration of superconductivity in the YBCO system.
A paper by J. Karpinski (ETH Zurich) et al. reports high-pressure crystal growth and physical properties of Hg-based superconductors and infinite chain (Ba,Ca,Sr)CuO2 compounds. High-pressure Ar gas is used to suppress the evaporation of mercury for the Hg containing compounds. The irreversibility field of Re doped Hg-1223 is lower than optimally doped Hg-1223.
Applications
A manuscript by M. D. Sumption (Ohio State) et al. reports the coupling current control in Rutherford cables wound with NbTi, Nb3Sn, and Bi(2212)/Ag. They find that the inclusion of a core enables the magnet builder to choose for the cable any of these conductors confident that in all cases, satisfactory values of the effective interstrand crossover contact resistance can be achieved.
The performance of long length, state-of-the-art Bi-2223 high- temperature superconductors are reported by M. W. Rupich (American Superconductor) et al. to be at a level required for initial introduction into commercial application in current limiters, power transmission cables, magnets, generators, and electric motors. Engineering current densities greater than 10,000 A/cm^2 are routinely achieved in composite conductors in lengths longer than 100 m. Filament critical current densities of 70,000 at 77 K and in self-field have been achieved in short length, rolled filamentary conductors.
Contributed by Douglas K. Finnemore
Contents: Preprints begin on page 4; Coming Events begin on page 10; and Resources are on page 11.
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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.
D. F. Agterberg, "Square Vortex Lattices for Two Component Superconducting Order Parameters." Submitted to Phys. Rev. B. Institut fuer Theoretische Physik, ETH-Hoenggerberg, CH-8093 Zurich, SWITZERLAND; telephone +41 1 633-2575 or -2570; telefax +41 1 633-1115; e-mail daniela@itp.ethz.ch; preprint also available at cond-mat@xxx.lanl.gov (#9806309). 74.20.Mn; 74.25.Bt.
A. S. Alexandrov, "Comment on 'Experimental and Theoretical Constraints of Bipolaronic Superconductivity in High-Tc Materials: An Impossibility.'" Department of Physics, Loughborough University, Loughborough, Leicestershire LE11 3TU, UNITED KINGDOM; telephone +44 1509 228409; telefax +44 1509 223986. 74.20.-z.
James F. Annett and J. P. Wallington, "s- and d-Wave Pairing in Short Coherence Length Superconductors." To be published in Symmetry and Pairing in Superconductors: Proc. of the NATO Advanced Research Workshop, Yalta, Crimea, Ukraine, April 28-May 2, 1998, edited by M. Ausloos (Kluwer 1998). H. H. Wills Physics Laboratory, University of Bristol, Royal Fort, Tyndall Avenue, Bristol BS8 1TL, UNITED KINGDOM; J. P. Wallington's e-mail jon.wallington@bristol.ac.uk; preprint also available at cond-mat@xxx.lanl.gov (#9807220).
N. Hari Babu, T. Rajasekharan, and V. Seshu Bai, "Melt Texturing of NdBa2Cu3O7-d-Nd4Ba2Cu2O10 Superconductor in Short Time." To be published in Eur. Phys. J. B. Interdisciplinary Research Centre in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE, UNITED KINGDOM; e-mail nhb24@cam.ac.uk. 74.80.Bj; 74.25.Ha; 74.60.Jg; 74.60.Ge.
G. Balestrino, C. Ferdeghini, S. Gariglio, D. Marre, P. G. Medaglia, G. Petrocelli, and A. S. Siri, "Magnetization and Magnetoresistivity Measurements on [(BaCuO2)2/(CaCuO2)2]n High Tc Superconducting Superlattices." To be published in Solid State Commun. Dipartimento di Scienze e Tecnologie Fisiche ed Energetiche, INFM-Universita di Roma "Tor Vergata", Via di Tor Vergata s.n.c., I-00133 Roma, ITALY; telephone +39 6 7259-7147 or -7148; telefax +39 6 7259-7145; e-mail balestrino@utovrm.it. Key words: high-Tc superconductors, thin films, nanostructures, flux pinning and creep.
B. I. Belevtsev, N. V. Dalakova, and A. S. Panfilov, "Non-Linear Effects in Hopping Conduction of Single-Crystal LaCuO4+d." To be published in Low Temp. Phys. Institute for Low Temperature Physics and Engineering, Ukrainian Academy of Sciences, 47 Lenin Ave., Kharkov 310164, UKRAINE; telefax +380 572 322370; e-mail belevtsev@ilt.kharkov.ua; preprint also available at cond-mat@xxx.lanl.gov (#9807297). 72.20.Ht; 74.72.Dn; 74.62.Dh; 74.80.-g.
Patrizia Benedetti and Roland Zeyher, "Holstein Model in Infinite Dimensions at Half-Filling." Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, GERMANY; telefax +49 711 689 1595; e-mail pata@audrey.mpi-stuttgart.mpg.de; preprint also available at cond-mat@xxx.lanl.gov (#9807094).
H. Bougrine, S. Dorbolo, R. Cloots, and M. Pekala, "Fluctuation Contributions to the Transport Properties of Hg1.4Ba2Ca2Cu3O8+d and Bi2Sr1.8Ca1.2Cu2O8." To be published in Symmetry and Pairing in Supercond., edited by M. Ausloos and S. Kruchinin (Kluwer, Dordrecht, 1998): Proc. of the NATO Adv. Res. Workshop, Yalta, Crimea, Ukraine, April 28-May 2, 1998. SUPRAS, Montefiore Institute of Electricity B28, University of Liege, B-4000 Liege, BELGIUM.
Charles Buhler and Adriana Moreo, "Study of Spin and Charge Fluctuations in the U-t-t' Model." Department of Physics, National High Magnetic Field Lab and MARTECH, Florida State University, 1800 E. Paul Dirac Dr., Tallahassee, FL 32306. 71.10.Fd; 71.18.+y; 74.25.Ha; 75.40.Mg.
X. Chen, N. J. Wu, A. Ignatiev, and Z. H. Zhang, "Structure and Conducting Properties of La0.5Sr0.5CoO3-d Films on YSZ." Preprint #98:061; submitted to J. Appl. Phys. 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.
J. L. Cohn, C. P. Popoviciu, Q. M. Lin, and C. W. Chu, "Hole Localization in Underdoped Superconducting Cuprates Near 1/8th Doping." Preprint #98:060; submitted to Phys. Rev. Lett. Department of Physics, University of Miami, Coral Gables, FL 33124; preprint also available from 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. 74.72.-h; 74.25.Fy; 74.25.Bt; 74.25.Dw.
R. Cristiano, L. Frunzio, C. S. Pagano, V. G. Palmieri, G. P. Pepe, H. Nakagawa, and M. P. Lisitskii, "A Hotspot Size Estimate Technique by Using Abrikosov Vortices in Josephson Tunnel Junctions." To be published in Appl. Supercond. (in press). Istituto di Cibernetica C.N.R., Via Toiano 6, I-80072 Arco Felice, Naples, ITALY.
S. Dorbolo and H. Bougrine, "Effects of Van Hove Singularities on Thermal Properties of High-Tc Superconductors." To be published in Symmetry and Pairing in Supercond., edited by M. Ausloos and S. Kruchinin (Kluwer, Dordrecht, 1998): Proc. of the NATO Adv. Res. Workshop, Yalta, Crimea, Ukraine, April 28-May 2, 1998. SUPRAS, Institute of Physics B5, University of Liege, B-4000 Liege, BELGIUM.
M. El Massalami, M. S. da Costa, M. A. Novak, and V. Barthem, "Magnetic Properties of the Quaternary Intermetallic Compounds RNiBC (R=Ho,Dy,Tb,Gd,Dy1-xGdx)." To be published in J. Magn. & Magn. Mater. Instituto de Fisica, Universidade Federal do Rio de Janeiro, C.P. 68- 528, 21945-970 Rio de Janeiro, RJ, BRAZIL; telephone +55 21 270 1191 ext. 231; telefax +55 21 280 7693; e-mail massalam@if.ufrj.br.
M. El Massalami, R. E. Rapp, and G. J. Nieuwenhuys, "Superconductivity in the Intermediate-Valence CeNi2B2C." To be published in Physica C. Instituto de Fisica, Universidade Federal do Rio de Janeiro, C.P. 68- 528, 21945-970 Rio de Janeiro, RJ, BRAZIL; telephone +55 21 270 1191 ext. 231; telefax +55 21 280 7693; e-mail massalam@if.ufrj.br. 74.72.Ny; 75.40.Cx; 74.25.Bt; 75.20.Hr.
J. Ferrer, M. A. Gonzalez-Alvarez, and J. Sanchez-Canizares, "Superflow in d-Wave Superconductors." Departamento de Fisica, Facultad de Ciencias, Universidad de Oviedo, E-33007 Oviedo, SPAIN; e-mail ferrer@condmat01.geol.uniovi.es; preprint also available at cond- mat@xxx.lanl.gov (#9806247). 74.72.-h; 74.60.Jg; 74.20.-z.
N. Hasselmann, A. H. Castro Neto, C. Morais Smith, and Y. Dimashko, "Dynamical Behavior of the Striped Phase in Presence of Disorder and Lattice Potentials." Department of Physics, University of California, Riverside, CA 92521; e-mail hasselma@theorie1.physnet.uni-hamburg.de; preprint also available at cond-mat@xxx.lanl.gov (#9807070). 71.45.Lr; 74.20.Mn; 74.72.Dn; 75.30.Fv.
Igor F. Herbut, "Finite Temperature Transport at the Superconductor- Insulator Transition in Disordered Systems." Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver B.C., CANADA V6T 1Z1; e-mail herbut@black-hole.physics.ubc.ca; preprint also available at cond-mat@xxx.lanl.gov (#9807152).
Seung-Pyo Hong and Sung-Ho Suck Salk, "Quasiparticle Energy Dispersion and Shadow Peaks in a Doped SO(5) Symmetric Ladder." Department of Physics, Pohang University of Science and Technology, Pohang 790-784, SOUTH KOREA; e-mail hong@anyon.postech.ac.kr; preprint also available at cond-mat@xxx.lanl.gov (#9807154). 74.25.Jb; 74.25.-q; 71.10.-w; 71.27.+a.
Shigeki Hontsu, Junya Ishii, Masaya Nakamori, Hitoshi Tabata, Tomoji Kawai, and Akira Fujimaki, "Metal/Ferroelectric/Superconductor Field Effect Transistor Using Pb(Zr0.52Tl0.48)O3/(Y0.6Pr0.4)Ba2Cu3O7-y Heterostructures." To be published in Appl. Supercond. (in press). Faculty of Biology Oriented Science and Technology, Kinki University, Uchita-cho, Naka-gun, Wakayama 649-64, JAPAN.
Pham V. Huong, "Anisotropy and Transport Properties in Substituted and Intercalated High Temperature Superconductors Studied by Raman Spectroscopy." Presented at the NATO Adv. Study Inst. -- Phys. and Mater. Sci. of the Vortex States, Flux Pinning, and Dynamics, Kusadasi, Turkey, July 26-Aug. 8, 1998. University of Bordeaux 1, 351 Cours Liberation, F-33405 Talence, FRANCE; telefax +33 556 848402; e-mail huong@morgane.lsmc.u-bordeaux.fr.
Magnus Hurd, Tomas Loefwander, Goeran Johansson, and Goeran Wendin, "ac Josephson Effect in Superconducting d-Wave Junctions." AXE Research and Development, Ericsson, Box 1505, S-125 25 Aelvsjoe, SWEDEN; Tomas Loefwander's e-mail at Chalmers University of Technology tfstomas@fy.chalmers.se; preprint also available at cond- mat@xxx.lanl.gov (#9807081). 74.50.+r; 74.20.-z.
J. Karpinski, H. Schwer, R. Molinski, G. I. Meijer, E. Kopnin, M. Angst, S. Buechi, J. Hofer, V. Alyoshin, R. Puzniak, and A. Wisniewski, "High Pressure Crystal Growth and Properties of Hg-Superconductors and Quasi- One-Dimensional Cuprates." Presented at the NATO Int. Workshop on High Temp. Supercond. and Novel Inorganic Mater. Eng. (MSU-HTSC V), Moscow, Russia, March 24-29, 1998. Laboratorium fuer Festkoerperphysik, ETH Hoenggerberg, CH-8093 Zurich, SWITZERLAND; telephone +41 1 633 2254; telefax +41 1 633 1072; e-mail karpinski@solid.phys.ethz.ch.
J. Karpinski, H. Schwer, R. Molinski, G. I. Meijer, E. Kopnin, M. Angst, J. Hofer, R. Puzniak, and A. Wisniewski, "High Pressure Crystal Growth and Physical Properties of Hg-Based Superconductors and Infinite-Chain A1-xCuO2 Compounds." Submitted to the Proc. of the 9th World Ceramic Congress and Forum on New Mater. (CIMTEC'98), Florence, Italy, June 14- 19, 1998. Laboratorium fuer Festkoerperphysik, ETH Hoenggerberg, CH- 8093 Zurich, SWITZERLAND; telephone +41 1 633 2254; telefax +41 1 633 1072; e-mail karpinski@solid.phys.ethz.ch.
Maarit Karppinen and Hisao Yamauchi, "The Doping Routes and Distribution of Holes in Layered Cuprates: A Novel Bond-Valence Approach." To be published in Phil. Mag. B. Contact Hisao Yamauchi, Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokoyama 227, JAPAN; telephone +81 45 924-5315; telefax +81 45 924-5635 or -5360; e-mail yamauchi@materia.titech.ac.jp.
H. J. Kaufmann, Oleg V. Dolgov, and E.K.H. Salje, "The Optical Response of Ba1-xKxBiO3: Evidence for an Unusual Coupling Mechanism of Superconductivity?" To be published in Phys. Rev. B. Interdisciplinary Research Centre in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE, UNITED KINGDOM; telephone +44 1223 33 34 09; telefax +44 1223 33 34 50; e-mail hjk22@cus.cam.ac.uk; preprint also available at cond-mat@xxx.lanl.gov (#9807314). 74.20.-z; 74.25.Gz; 74.20.Mn; 74.72.Yg.
S. Kittelberger, O. M. Stoll, and R. P. Huebener, "Oxygen Diffusion in Thin YBa2Cu3O7-d Films Studied from Isothermal Electric Resistivity Measurements." To be published in Supercond. Sci. & Technol. Physikalisches Institut, Lehrstuhl fuer Experimentalphysik II, Universitaet Tuebingen, Morgenstelle 14, D-72076 Tuebingen, GERMANY; telefax +49 7071 295406; e-mail kittelberger@brahms.pit.physik.uni- tuebingen.de. 66.30.-h; 74.76.Bz; 74.25.Fy.
T. Klein, A. Conde-Gallardo, J. Marcus, C. Escribe-Filippini, P. Samuely, P. Szabo, and A.G.M. Jansen, "The Vortex Glass Transition in the (K,Ba)BiO3 Cubic Superconductor." To be published in Phys. Rev. B. Laboratoire d'Etudes des Proprietes Electroniques des Solides, Centre National de la Recherche Scientifique, BP166, F-38042 Grenoble Cedex 9, FRANCE; telephone +33 4 76 88 1008; telefax +33 4 76 88 7988; e-mail klein@lepes.polycnrs-gre.fr. 74.60.Ge; 74.25.Fy; 74.40.+k.
Y. Kopelevich and P. Esquinazi, "Second Magnetization Peak at Low Fields Due to Thermomagnetic Flux-Jump Instability." To be published in J. Low Temp. Phys. Department of Superconductivity and Magnetism, Universitaet Leipzig, Linnestr. 5, D-04103 Leipzig, GERMANY. 74.60.Ge; 74.72.-h; 74.76.-w.
A. E. Koshelev, L. N. Bulaevskii, and M. P. Maley, "Josephson Plasma Resonance as a Structural Probe of Vortex Liquid." To be published in Phys. Rev. Lett. Contact Janice Coble, Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telephone (630) 252-5497; telefax (630) 252-9595; e-mail coble@anl.gov; preprint also available at cond-mat@xxx.lanl.gov (#9807043).
G. Krabbes, P. Schaetzle, W. Bieger, and G. Fuchs, "Modified Melt Crystallization Processes for Improved RE-123 Based Bulk Materials (RE=Y,Nd)." To be published in Appl. Supercond. IFW Dresden Institute of Solid State and Materials Research, P.O. Box 270016, D-01171 Dresden, GERMANY; telephone +49 351 4659 410; telefax +49 351 4659 480.
W. K. Kwok, L. Paulius, D. Lopez, H. Safar, R. J. Olsson, A. M. Petrean, and G. W. Crabtree, "Induced Point and Correlated Disorder Pinning in Untwinned YBa2Cu3O7-d Crystals." Submitted to the Int. Rare Earths Conf. '98', Fremantle, Australia, Oct. 25-30, 1998. Contact Janice Coble, Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telephone (630) 252-5497; telefax (630) 252-9595; e-mail coble@anl.gov. Key words: superconductivity, vortex pinning.
Gordey B. Lesovik and Gianni Blatter, "Nonlinear Transport Through NS Junctions Due to Imperfect Andreev Reflection." Institute of Solid State Physics, Russian Academy of Sciences, 142432 Chernogolovka, Moscow District, RUSSIA; Gianni Blatter's e-mail at Zurich, Switzerland, blatterj@itp.phys.ethz.ch; preprint also available at cond- mat@xxx.lanl.gov (#9807178). 74.80.Fp; 74.50.+r; 72.10.-d; 72.20.Ht.
H. L. Liu, G. Blumberg, M. V. Klein, P. Guptasarma, and D. G. Hinks, "c- Axis Electronic Raman Scattering in Bi2Sr2CaCu2O8+d." Submitted to Phys. Rev. B. Department of Physics and Science Technology Center for Superconductivity, University of Illinois at Urbana-Champaign, Urbana, IL 61801-3080; preprint also available from Janice Coble, Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telephone (630) 252-5497; telefax (630) 252-9595; e- mail coble@anl.gov. 74.72.Hs; 78.20.-e; 78.30.-j.
J.-P. Locquet, J. Perret, J. Fompeyrine, E. Maechler, J. W. Seo, and G. Van Tendeloo, "Doubling the Critical Temperature of La1.9Sr0.1CuO4 Using Epitaxial Strain." To be published in Nature. IBM Research Division, Zurich Research Laboratory, Saeumerstrasse 4, CH-8803 Rueschlikon, SWITZERLAND; telephone +41 1 724 8111; telefax +41 1 724 0084; e-mail loc@zurich.ibm.com.
R. S. Markiewicz, "Stripes Have Hair." Department of Physics and Barnett Institute, Northeastern University, 360 Huntington Avenue, Boston, MA 02115; telephone (617) 373-2916; telefax (617) 373-2943; e- mail markiewic@neu.edu; preprint also available at cond-mat@xxx.lanl.gov (#9807230).
R. S. Markiewicz, C. Kusko, and V. Kidambi, "Pinned Balseiro-Falicov Model of Tunneling and Photoemission in the Cuprates." Department of Physics and Barnett Institute, Northeastern University, 360 Huntington Avenue, Boston, MA 02115; telephone (617) 373-2916; telefax (617) 373- 2943; e-mail markiewic@neu.edu; preprint also available at cond- mat@xxx.lanl.gov (#9807068).
R. S. Markiewicz, C. Kusko, and M. T. Vaughn, "Tunneling and Photoemission in an SO(6) Superconductor." To be published in J. Supercond.: Proc. of the Int. Conf. on Stripes, Lattice Instabilities, and High Tc Supercond., Rome, Italy, June 2-7, 1998. Department of Physics and Barnett Institute, Northeastern University, 360 Huntington Avenue, Boston, MA 02115; telephone (617) 373-2916; telefax (617) 373- 2943; e-mail markiewic@neu.edu; preprint also available at cond- mat@xxx.lanl.gov (#9807067). Key words: high-Tc cuprates, underdoped, pseudogap, striped phases.
A. Mazilu, H. Safar, D. Lopez, W. K. Kwok, G. W. Crabtree, P. Guptasarma, and D. G. Hinks, "Experimental Comparison of the Effect that Bulk Pinning and Surface Barriers Have on Vortex Motion in the Vortex Liquid State of Bi2Sr2CaCu2O8 Single Crystals." Submitted to Phys. Rev. B. Department of Physics, University of Illinois at Chicago, 845 W. Taylor 2236, Chicago, IL 60607-7059; preprint also available from Janice Coble, Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telephone (630) 252-5497; telefax (630) 252-9595; e-mail coble@anl.gov.
V. Metlushko, U. Welp, G. Crabtree, Zhao Zhang, S.R.J. Brueck, B. Watkins, L. E. DeLong, B. Ilic, K. Chung, and P. J. Hesketh, "Non-Linear Flux Line Dynamics in Vanadium Films with Square Lattices of Submicron Holes." Submitted to Phys. Rev. B. Contact Janice Coble, Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telephone (630) 252-5497; telefax (630) 252-9595; e- mail coble@anl.gov. 74.60.Ge; 74.25.Ha; 74.76.Db.
Dirk K. Morr and David Pines, "Effect of Superconductivity on the Incommensurate Magnetic Response of Cuprate Superconductors." Loomis Laboratory of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, IL 61801; telephone (217) 244-6242; telefax (217) 244-7559; e-mail morr@physics.uiuc.edu; preprint also available at cond-mat@xxx.lanl.gov (#9807214). 74.25.-q; 74.25.Ha; 74.25.Jb.
Dirk K. Morr and David Pines, "The Resonance Peak in Cuprate Superconductors." To be published in Phys. Rev. Lett. Loomis Laboratory of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, IL 61801; telephone (217) 244-6242; telefax (217) 244-7559; e-mail morr@physics.uiuc.edu.
Niels Asger Mortensen, Karsten Flensberg, and Antti-Pekka Jauho, "Angle Dependence of Andreev Scattering at Semiconductor-Superconductor Interfaces." Submitted to Phys. Rev. B. Department of Physics, Bldg. 309/060, Technical University of Denmark, DK-2800 Lyngby, DENMARK; telephone +45 4525 3243; telefax +45 4593 1669; e-mail asger@fysik.dtu.dk. 73.40.Gk; 74.90.+n; 85.25.-j.
M. Pekala, W. Gadomski, I. Nedkov, H. Bougrine, and M. Ausloos, "Vortex Lattice Melting and Viscosity in Y0.6Dy0.4Ba2Cu3O7-x Superconductor Studied by Electrical Resistivity." To be published in Symmetry and Pairing in Supercond., edited by M. Ausloos and S. Kruchinin (Kluwer, Dordrecht, 1998): Proc. of the NATO Adv. Res. Workshop, Yalta, Crimea, Ukraine, April 28-May 2, 1998. Department of Chemistry, University of Warsaw, Al. Zwirki i Wigury 101, PL-02-089 Warsaw, POLAND.
Catherine Pepin and Patrick A. Lee, "Order from Disorder: Nonmagnetic Impurities in the Spin-Gap Phase of the Cuprates." Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139; e- mail catherin@mit.edu; preprint also available at cond-mat@xxx.lanl.gov (#9802260).
Eugene Pivovarov, "Hubbard Model with SU(4) Symmetry." Preprint #CALT- 68-2187. California Institute of Technology, 103-33, Pasadena, CA 91125; e-mail evgueny@cco.caltech.edu; preprint also available at cond- mat@xxx.lanl.gov (#9807312). 71.10.Fd; 74.20.Mn; 74.25.-q.
A. Poenicke, Yu. S. Barash, C. Bruder, and V. Istyukov, "Broadening of Andreev Bound States in d_[x^2-y^2] Superconductors." Submitted to Phys. Rev. B. Institut fuer Theoretische Festkoerperphysik, Universitaet Karlsruhe, Engesserstr. 7, Physikhochhaus, D-76128 Karlsruhe, GERMANY; telephone +49 721 608 7012; telefax +49 721 69 8150; e-mail poeni@tfp.physik.uni-karlsruhe.de; preprint also available at cond-mat@xxx.lanl.gov (#9807052).
D. M. Potrepka, J. I. Budnick, D. B. Fenner, M. Balasubramanian, and W. A. Hines, "Local Cu and Br Environments and Their Relationship to Superconductivity Restoration in Brominated YBa2Cu3Oy." To be published in Appl. Phys. Lett. Department of Physics, U-46, University of Connecticut, Storrs, CT 06269-3046; telephone (860) 486-4963; telefax (860) 486-3346; e-mail potrepka@phys.uconn.edu.
Ruslan Prozorov, "Static and Dynamic Irreversible Magnetic Properties of High Temperature Superconductors." Submitted as a Ph.D. thesis (Bar- Ilan University). Department of Physics, Institute of Superconductivity, Bar-Ilan University, 52900 Ramat-Gan, ISRAEL; e-mail prozorr@mail.biu.ac.il.
L. Pust, L. E. Wenger, and M. R. Koblischka, "Detailed Investigation of the Superconducting Transition of Niobium Disks Exhibiting the Paramagnetic Meissner Effect." Submitted to Phys. Rev. B. Contact L. E. Wenger, Department of Physics and Astronomy, Wayne State University, Detroit, MI 48202; telephone (313) 577-2520; telefax (313) 577-9693; e- mail lwenger@science.wayne.edu; preprint also available at cond- mat@xxx.lanl.gov (#9807109). 74.60.Ec; 74.60.Ge; 74.60.Jg.
R. Puzniak, J. Karpinski, A. Wisniewski, R. Szymczak, M. Angst, H. Schwer, R. Molinski, and E. M. Kopnin, "Influence of Re Substitution on the Flux Pinning in (Hg,Re)Ba2Ca2Cu3O8+d Single Crystals." Submitted to Physica C. Contact J. Karpinski, Laboratorium fuer Festkoerperphysik, ETH Hoenggerberg, CH-8093 Zurich, SWITZERLAND; telephone +41 1 633 2254; telefax +41 1 633 1072; e-mail karpinski@solid.phys.ethz.ch.
F. Raffa, M. Mali, J. Roos, D. Brinkmann, M. Matsumura, and K. Conder, "Low Energy Excitation in the Infinite-Layer Antiferromagnet Ca0.85Sr0.15CuO2." To be published in Phys. Rev. B. Physik-Institut, Universitaet Zurich, CH-8057 Zurich, SWITZERLAND; e-mail fraffa@physik.unizh.ch.
F. Raffa, T. Ohno, M. Mali, J. Roos, D. Brinkmann, K. Conder, and M. Eremin, "Isotope Dependence of the Spin Gap in YBa2Cu4O8 as Determined by Cu NQR Relaxation." Submitted to Phys. Rev. Lett. Physik-Institut, Universitaet Zurich, CH-8057 Zurich, SWITZERLAND; e-mail fraffa@physik.unizh.ch. 74.72.-h; 74.25.Nf; 74.62.Dh.
M. W. Rupich, Q. Li, R. D. Parrella, M. Teplitsky, E. R. Podtburg, W. L. Carter, S. Hancock, J. Marquardt, J. D. Schreiber, D. R. Parker, G. N. Riley, Jr., L. J. Masur, P. K. Miles, and T. G. Holesinger, "Critical Current Density Enhancement in Bi-2223 Composites." To be presented at the 1998 Int. Workshop on Supercond.: Mater. and Technol. Issues for HTS Wires and Bulk Applications, Okinawa, Japan, July 12-15, 1998. American Superconductor Corporation, Two Technology Drive, Westborough, MA 01581-1727; telephone (508) 836-4200; telefax (508) 836-4248; e-mail jcrail@amsuper.com.
R. T. Scalettar, N. Trivedi, and C. Huscroft, "Quantum Monte Carlo Study of the Disordered Attractive Hubbard Model." Department of Physics, University of California at Davis, Davis, CA 95616; N. Trivedi's e-mail at Mumbai, India, ntrivedi@theory.tifr.res.in; preprint also available at cond-mat@xxx.lanl.gov (#9807008). 74.20.Mn; 74.20.-z; 71.55.Jv.
Sergei A. Sergeenkov and Jorge V. Jose, "Analog of Magnetoelectric Effect in High-Tc Granular Superconductors." To be published in Europhys. Lett. Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, RUSSIA; e- mail ssa@thsun1.jinr.dubna.su; preprint also available at cond- mat@xxx.lanl.gov (#9807098).
V. Shapiro, I. Lapsker, A. Verdyan, and J. Azoulay, "Flux-Flow Hall Effect in YBaCuO Ceramics." Contact J. Azoulay, Center for Technological Education Holon, 52 Golomb St., P.O.B. 305, Holon 58102, ISRAEL; telephone +972 3 5026608; telefax +972 3 5026720.
Mikhail Strikovski and John H. Miller, Jr., "Pulsed Laser Deposition of Oxides: Why the Optimum Rate is about 1 Angstrom per Pulse." To be published in Appl. Phys. Lett. Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5932; telephone (713) 743-8200; telefax (713) 743-8201; e-mail mstrikov@bayou.uh.edu or preprints@www.tcs.uh.edu.
Gang Su and Masuo Suzuki, "Universal Relation Connecting Fermi Surface to Symmetry of the Gap Function in BCS-Like Superconductors." Department of Applied Physics, Faculty of Science, Science University of Tokyo, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162, JAPAN; telephone +81 3 3260 4271; telefax +81 3 3260 4772; e-mail gsu@ap.kagu.sut.ac.jp; preprint also available at cond-mat@xxx.lanl.gov (#9807346). 74.20.Fg; 71.18.+y; 74.25.-q.
Hideyuki Sugiyama, Keiichi Kobata, Akira Fujimaki, and Hisao Hayakawa, "Characteristics of Nb Junctions with Additional Al/AlOx." To be published in Appl. Supercond. (in press). Department of Quantum Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-01, JAPAN.
M. D. Sumption, R. M. Scanlan, and E. W. Collings, "Coupling Current Control in Rutherford Cables Wound with NbTi, Nb3Sn, and Bi:2212/Ag." To be published in Physica C: Proc. of the Int. Cryogenic Mater. Conf. (ICMC'98), Enschede, The Netherlands, May 10-13, 1998. Department of Materials Science and Engineering, 477 Watts Hall, Ohio State University, 2041 College Avenue, Columbus, OH 43210-1179; telephone (614) 688-3684; telefax (614) 292-1537; e-mail mdsumption+@osu.edu. Key words: Rutherford cable, cores, NbTi, Nb3Sn, Bi:2212/Ag, ac loss, contact resistance.
M. I. Tsindlekht, E. B. Sonin, M. A. Golosovsky, D. Davidov, X. Castel, M. Guilloux-Viry, and A. Perrin, "Microwave Properties of YBa2Cu3O7-d Thin Films in Linear and Nonlinear Regime in a dc Magnetic Field." Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, ISRAEL; telephone +972 2 658 338; telefax +972 2 617 805; e-mail mtsindl@vms.huji.ac.il.
C. C. Tsuei and T. Doderer, "Quantum Level Effect in Cuprate Superconductors: A Possible Explanation for the Normal-State Pseudogap." Submitted to Nature. IBM Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, NY 10598; T. Doderer's telephone (914) 945-4201; telefax (914) 945-2141; e-mail doderer@watson.ibm.com.
M. Velez, M. C. Cyrille, S. Kim, J. L. Vicent, and Ivan K. Schuller, "Enhancement of Superconductivity by Decreased Magnetic Spin-Flip Scattering: Nonmonotonic Tc Dependence with Enhanced Magnetic Ordering." Submitted to Phys. Rev. Lett. Departamento de Fisica de Materiales, Facultad de Fisicas, Universidad Complutense, E-28040 Madrid, SPAIN.
A. Virosztek and J. Ruvalds, "Susceptibility Scaling and Vertex Corrections for a Nested Fermi Liquid." Institute for Physics, Technical University of Budapest, and Research Institute for Solid State Physics and Optics, P.O.B. 49, H-1525 Budapest, HUNGARY; J. Ruvalds' telephone at University of Virginia (804) 924-6796; telefax (804) 924- 4576; e-mail jr7k@virginia.edu. 74.10.+v; 74.20.Mn; 74.72.-h.
M. Vojta and E. Dagotto, "Indications of Unconventional Superconductivity in Doped Triangular Antiferromagnets." Submitted to Phys. Rev. Lett. Institut fuer Theoretische Physik, Technische Universitaet Dresden, D-01062 Dresden, GERMANY; telephone +49 351 463 6074; telefax +49 351 463 7079; e-mail vojta@theory.phy.tu-dresden.de; preprint also available at cond-mat@xxx.lanl.gov (#9807168). 74.20.-z; 74.20.Mn; 75.50.Ee.
Orlando S. Wagner, Guido Burkard, Vadim B. Geshkenbein, and Gianni Blatter, "Thermal Suppression of Strong Pinning." To be published in Phys. Rev. Lett. Theoretische Physik, ETH-Hoenggerberg, CH-8093 Zurich, SWITZERLAND; e-mail orlando@itp.phys.ethz.ch; preprint also available at cond-mat@xxx.lanl.gov (#9803119). 74.60.Ge; 74.60.Jg.
Matthias Weiss, Wulf Guenther, and Robert Schoellhorn, "Topotactic Cathodic Reduction of the Superconducting Oxocuprate YBa2Cu3O7." To be published in Physica C. Contact Robert Schoellhorn, Institut fuer Anorganische und Analytische Chemie, Technische Universitaet Berlin, Strasse des 17. Juni 135, D-10623 Berlin, GERMANY; telephone +49 30 314 22740; telefax +49 30 314 21106; e-mail schoe@wap0209.chem.tu-berlin.de. Key words: oxocuprates, superconductivity, hydrogen intercalation, electrochemistry.
J. Wosik, L. M. Xie, M. Strikovski, J. H. Miller, Jr., and P. Przyslupski, "Microwave Characterization of Nd0.67Sr0.33MnO3-x Thin Films for Magnetically Tunable Filters." Preprint #98:063; submitted to Appl. Phys. Lett. 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.
Takashi Yasuda, Tetsuji Uchiyama, Takeshi Fukami, Takafumi Aomine, and Shuzo Takano, "Interlayer Critical Current in the Vortex State of Bi2Sr2CaCu2O8+d Intrinsic Junctions." To be published in Appl. Supercond. (in press). Department of Computer Science and Electronics, Kyushu Institute of Technology, Iizuka, Fukuoka 820, JAPAN.
H. Zheng, M. Jiang, Yi Huang, B. W. Veal, and H. Claus, "Growth and Physical Properties of Melt Textured (Gd,Y)Ba2Cu3Ox." Submitted to Physica C. Contact Janice Coble, Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telephone (630) 252-5497; telefax (630) 252-9595; e-mail coble@anl.gov.
A. A. Zhukov, G. K. Perkins, L. F. Cohen, A. D. Caplin, H. Kuepfer, T. Wolf, and G. Wirth, "Narrow Dip in the Angular Dependence of the Irreversible Magnetic Moment in Columnar-Defected YBa2Cu3Oy Single Crystals." Submitted to Phys. Rev. B. Department of Physics, Moscow State University, Moscow 117234, RUSSIA. 74.60.Ge; 74.60.Jg; 74.72.Bk.
COMING EVENTS (An * indicates a previously listed event.)
*Sept. 14 - 26, 1998: Third Training Course in the Physics of Correlated Electron Systems and High-Tc Superconductors, Vietri sul Mare, Salerno, Italy. The School, aimed at postdoctoral-level researchers, will offer opportunity for students to meet experts in various fields of strongly correlated electron systems. The proposed project of practical training courses intends to promote the theoretical research in the field of highly correlated electron systems by putting together senior researchers with experience and skill and young researchers. The courses will be open to a limited number (25) of young European researchers. Registration fee: $250. Limited number of grants for European researchers covering part of the costs will be available. Topics are: electron-phonon coupled systems (polaronic systems), high-Tc cuprates, manganates, dynamical mean field theory, (quantum impurity models, large spatial coordination, Falikov-Kimball model, Anderson impurity model, and Mott transition), and Green's function Monte Carlo for strongly correlated systems. Application form and grant request form are available from Prof. F. Mancini, Dipartimento di Scienze Fisiche "E. R. Caianiello", Universita' di Salerno, Via S. Allende, I-84081 Baronissi (SA), Italy; telephone +39 89 965 322; telefax +39 89 965 275; e-mail mancini@vaxsa.csied.unisa.it.
*Oct. 19 - Nov. 6, 1998: Experimental Workshop on High Temperature Superconductors and Related Materials, San Carlos de Bariloche, Argentina. Organized by International Centre for Theoretical Physics (ICTP) and Centro Atomico Bariloche (CAB). This is the second workshop and intends to provide a general view of the state-of-the-art in the different areas of research. Main purpose is to present to the participants the personal view of the invited speakers on new research areas to be developed in the near future. Topics to be covered are: nature of the normal and superconducting state of copper oxides; thermodynamics and transport properties of the vortex structure in the liquid and solid state; normal and superconducting properties of artificial low-dimensional systems; new superconducting and related materials; material properties and characterization; optical properties of high-temperature superconductors; nonconventional superconductors; and trends in applications of HTSC materials. Workshop is open to research workers from all countries that are members of the United Nations, UNESCO, or IAEA. No registration fee. For information, contact the Abdus Salam International Centre for Theoretical Physics, P.O. Box 586, I-34100 Trieste, Italy; telephone +39 40 2240111; telefax +39 40 224163.
*Dec. 14 - 16, 1998: Conference on Advances in Superconductivity and Its Applications in Microwaves (ASAM'98). Intends to provide a forum to review the progress and obstacles in the field of superconductivity and to find solutions to these problems. Topics to be covered are: new superconducting materials and their novel aspects; critical currents; theoretical aspects of high-Tc superconductivity; microwave superconductivity; thin films and devices; vortex structures, pinning, and dynamics; semiconductor-superconductor microwave circuits; and other related topics such as GMR/CMR, etc. Abstract deadline, August 31, 1998; registration deadline, October 31, 1998. For further information, contact R. P. Tandon, Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India; telephone +91 11 725 7793; telefax +91 11 725 7061; e-mail ram@csec.ernet.in or chilana@csec.ernet.in.
Jan. 7 - 13, 1999: 1999 University of Miami Conference on High Temperature Superconductivity, Miami, Fla. Third in the series. Goal of this conference is to provide a forum for engaging researchers in a focused dialog directed at exploring and distilling the latest experimental and theoretical results in the field likely to have significant influence on the understanding of the normal-state properties and origin of superconductivity in this class of materials. The format will involve a relatively small number (150) of researchers assembled in common sessions. The conference, in addition to addressing physical properties, microscopic theory, and mechanisms for high- temperature superconductivity, will include other related topics (e.g. ladders, manganites, and nickelates). Partial list of topics for which abstracts are solicited includes: pseudogap, stripes/AF correlations, gap symmetry/tunneling, vortex properties, electronic structure, photoemission, non-Fermi liquids, mechanisms, new materials, other oxides (Mn, Ni, etc.), and ladder compounds. Abstract deadline, October 2, 1998. Contributed presentations will primarily be in the form of posters, although a small number may be selected for oral presentation. For information contact HTS99@physics.miami.edu. Further details are available on the world-wide web at http://phyavx.ir.miami.edu:8001/hts99.
*July 12 - 16, 1999: Cryogenic Engineering Conference & International Cryogenic Materials Conference (CEC/ICMC), Hotel Inter-Continental Montreal, Montreal, Quebec, Canada. The CEC focuses on the science and engineering required for cryogenic applications such as liquefied gases for fuels; space applications of cryogenic liquids; cooling and performance of superconducting magnet systems in medical, transportation, power, and basic research applications; as well as the systems, machinery, control technology, and thermodynamics required to produce low temperatures. The ICMC focuses on the development, characterization, fabrication, and optimization of the materials used in cryogenic applications, typically broken into two broad categories: structural materials and superconducting materials. ICMC contributions cover both high- and low-temperature superconducting materials from basic materials research through behavior of composite cables and wires in applications. Cryogenic structural materials cover a broad range, including nonmetallic composites, polymeric resins and insulation materials, ferrous alloys, nickel-base alloys, aluminum alloys, and specialized materials for advanced cryocooler applications. Abstract deadline, November 1,1998 (for mailed submissions) and December 11, 1998 (for Web submissions). For information, contact Centennial Conferences, 4800 Baseline Road, Suite A-112, Boulder, CO 80303; telephone (303) 499- 2299; telefax (303) 499-2599; e-mail centennial@orci.com; Web site http://www.cec-icmc.org.
*Aug. 4 - 11, 1999: 22nd International Conference on Low Temperature Physics (LT22), Espoo and Helsinki, Finland. Topics will include: quantum gases, fluids and solids; superconductivity; magnetism and lattice properties; quantum electron transport; applications; materials; and techniques. For information, contact Conference Service Bureau, TSG-Congress Ltd., Kaisaniemenkatu 3 B 31, FIN-00100 Helsinki, Finland; telephone +358 9 628044; telefax +358 9 667675; e-mail info@tsgcongress.fi. For technical information, contact the LT22 Office, Low Temperature Laboratory, Helsinki University of Technology, P.O. Box 2200, FIN-02015 HUT; telephone +358 9 451 2962; telefax +358 9 451 2969; e-mail info@LT22.hut.fi; Web site http://lt22.hut.fi/LT22/LT22.html.
RESOURCES
Information
New Book: Low Level Measurements -- Precision dc Current, Voltage and Resistance Measurements, edited by John Yeager and Mary Anne Hrusch- Tupta (Keithley). Intended as a practical guide to making precision measurements and useful both as a reference handbook and as an aid to understanding low-level phenomena. Provides overview of the theoretical and practical considerations involved in measuring low currents, high and low resistances and low voltages. Discusses unique problems of measuring low voltages and currents and discusses practical measuring methods and applications. Book also covers design characteristics of the growing variety of low-level measurement instruments including electrometers, picoammeters, nanovoltmeters, micro-ohmmeters, SourceMeters, and Source Measure Units. For information, contact Keithley Instruments, Inc., 28775 Aurora Road, Cleveland, OH 44139; telephone (440) 248-0400; telefax (440) 248-6168; Web site http://www.keithley.com.
Products and Services
The Model 2015 Total Harmonic Distortion Multimeter from Keithley Instruments, Inc., can be used for a broad range of voltage, resistance, current, frequency, distortion, and harmonic magnitude measurements. Includes an internal audio band sine-wave source for generating stimulus signals. This and other capabilities make the model suitable for use in a variety of applications including audio quality testing of wireless communication devices such as cell phones, pagers, etc. and microphones for these devices. For information, contact Keithley Instruments, Inc., 28775 Aurora Road, Cleveland, OH 44139-1891; telephone (440) 248-0400; telefax (440) 248-6168; Web site http://www.keithley.com.
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.
The information contained herein is intended for limited distribution. Readers are expected to respect the rights of the authors.
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: MITRA@AMESLAB.GOV or MITRA@IASTATE.EDU.
Project Director/Editor: Sreeparna Mitra
Science Editor: John R. Clem
High-Tc Update, Vol. 12, #16, August 15, 1998.