Published for the Division of Materials Sciences, Office of Basic Energy Sciences, USDOE, under Contract W-7405-eng-82 with the Ames Laboratory, Iowa State University. Funded by DMS/BES/USDOE, ARPA, NSF, and other agencies, organizations, and individuals.

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PLEASE NOTE: Issues of High-Tc Update from November 15, 1993, onward are also available in coded Word versions (BINHEX and RTF). (These versions preserve the Greek letters, special characters, accents, etc.) If you are interested in the alternate formats, contact the editor for information.

PLEASE READ: The electronic-mail version of High-Tc Update is generated from a Macintosh Microsoft Word file and turned into a text file that can be transferred electronically. Formatting commands, Greek symbols, diacritical marks, etc. are lost in this transformation. In order to improve the readability of the e-mail version, the newsletter staff add explanatory marks as needed to the text file. For example, a carat (10^5) indicates a superscript (ten to the fifth). A carat followed by a bracket (cm^[-2]) indicates everything within the brackets is superscripted (centimeter to the minus 2). A bracket followed by a carat ([18]^O) indicates everything before the carat is superscripted. An underline (M_i) indicates a subscript (M subscript i). Most Greek letters are spelled out (Delta, mu, tau, pi, Omega), although delta is left as "d." In most instances, easily recognizable formulas or units are left as they appear: Tc, Jc, YBa2Cu3O7, O2. Mu-m is changed to micrometers. Diacritical marks (accents, tildes, carats, etc.) are removed, but the German umlaut (e.g., a, o, or u with two dots over it) is changed into a, o, or u followed by e. If needed for clarity, hyphens are occasionally inserted between spelled-out Greek letters or symbols (ohm-cm, sin-theta).

NOTA BENE: The following Nota Bene is contributed by Douglas K. Finnemore, Distinguished Professor and Chair of Physics, Iowa State University, and Senior Physicist at Ames Laboratory. Our Science Editor, John R. Clem, is currently on travel.

Theory

Nonequilibrium properties of short-coherence-length s-wave superconductors have been analyzed in the presence of extrinsic and intrinsic inhomogeneities by M. I. Salkola et al. (Tallahassee). They examine various metastable configurations of quasiparticles and their signatures that might develop when spin-polarized quasiparticles are excited in s-wave superconductors. The most important finding is that superconductors are unstable against a formation of antiphase domain walls into which the quasiparticles localize. The local structure and nonuniform spin density makes these topological textures accessible to experimental probes such as NMR and muSR. In general, the lowest energy configurations of quasiparticle excitations are lamillar structures in which quasiparticles segregate into antiphase domain walls between superconducting regions whose order parameter phases differ by 180 degrees.

A preprint by E. Langmann (Stockholm) et al. reports a mean-field analysis of a model of superconductivity in an antiferromagnetic background. It is a description of the coexistence of anti- ferromagnetic correlations and superconductivity that may have application to high-temperature superconductors. Using a path integral formulation, they construct mean-field equations that are used to evaluate the superconducting transition temperature, the energy gap, the tunneling density of states, and the tunneling conductivity. Antiferromagnetism is shown to raise the superconducting transition temperature.

The structure of the Fulde-Ferrell-Larkin-Ovchinnikov state in two- dimensional superconductors has been reported by H. Shimahara (Hiroshima). A nonuniform superconducting state due to strong spin magnetism is studied in (2D) type-II superconductors near the second- order phase-transition line between the superconducting and normal state. For s-wave pairing, triangular, square, or a hexagonal state may be favored depending on the temperature.

As reported by V. Vinokur (Argonne) et al., a theoretical analysis in terms of an extended Lindemann criterion provides a quantitative description of the vortex-matter phase boundaries and the behavior of the transition lines with varying anisotropy and disorder. They show that at least three distinct phases exist, a relatively ordered quasi- lattice, a highly disordered entangled vortex solid, and a liquid phase.

A preprint by W. Belzig (Karlsruhe) et al. investigates the electronic structure of twin boundaries in orthoganally distorted materials. At low temperatures, they find a local instability to a time-reversal symmetry breaking state at the twin boundary that yields spontaneous currents along the twin. They calculate the local density of states and find the splitting in the zero-bias peak once the spontaneous currents set in.

Pseudogap behavior in dynamical properties of high-Tc cuprates is reported by T. Sakai et al. (Hyogo, Japan). Dynamical properties of 2D antiferromagnets with hole doping are investigated to see the effects of short-range local magnetic order on the temperature dependence of the NMR relaxation rate.

A paper by R. Eder (Wurzburg) et al. reports numerical calculations that support SO(5) symmetry as a concept unifying superconductivity and antiferromagnetism in the high-temperature cuprates. Their results show that the d-wave superconducting ground states away from half filling are obtained from the higher spin states at half filling through SO(5) rotations.

R(123)

A paper by C. C. Homes (Brookhaven) et al., deals with the technical problem of evaluating the condensate in superconducting systems in which not all the free carriers condense. The problem is first dealt with for the case of nominally pure oxygen-overdoped Y(123) where both optical and microwave results are available. Using the more reliable microwave estimate for the condensate, the combination of the optical and microwave then give a more complete understanding of the normal and superconducting states.

Reversible magnetization data in strong pinning Y(123) thin films is reported by V. K. Souw (Purdue) et al. as the angle between the applied field and the film normal is systematically varied. The magnetization is nearly reversible when the field direction lies close to the plane of the film. The angular range of reversibility gets smaller as the temperature rises. The shape of the in-plane component of the magnetization does not conform to the Bean model for strong flux pinning.

The ortho-II crystallographic superstructures of Y(123) having 6.5 oxygen per unit cell is reported for temperatures between 20 K and 410 K in a paper by E. Straube et al. (Berlin). X-ray structure refinements with intensities of 160 symmetry independent superstructure reflections show that the antiferro-distortive displacements of Y and Ba increase at lower temperatures. There is no significant change in the displacements at Tc. In the range between 298 K and 393 K, the ortho-II structure is gradually destroyed. The relation between the degree of oxygen order and the superconducting transition temperature is established for Tc values between 50 K and 53 K.

High-temperature thermodynamic properties and the phase stability have been reported by F. Prado et al. (Bariloche) for Gd(123) and related rare-earth compounds. The effect of the R atom ion size on the oxygen stoichiometry and phase stability is discussed and a possible explanation is proposed which accounts for the lattice mismatch between the Ba-O and CuO2 layers.

A microprobe Raman scattering technique has been used by K. Mori et al. (Muroran) to study the temperature and carrier dependence of the phonons in Y(124). The phonon anomalies observed above Tc were strongly dependent on carrier density and increased with temperature up to 200 K. Strong correlations between the carrier density and the frequency shift was observed for the 315 cm^[-1]Raman mode.

S. Djordjevic (Paris) et al. have reported the low-temperature penetration depth and the effect of quasiparticle scattering measured by millimeter wave transmission for Y(123). They compare the data to the predictions of the d-wave model incorporating resonant scattering and do not find satisfactory agreement.

An unusual resistivity broadening in the mixed state of Nd(123) crystals grown by a crystal-pulling technique is reported by T. Mimura et al. (ISTEC). The results suggest the existence of sheet-like pinning centers perpendicular to the conduction planes.

A preprint by H. Darhmaoui et al. (Edmonton) reports the dissipation of persistent currents and associated vortex dynamics in Y(123) thin films in the remanent magnetization regime. They show a universal behavior of both the temperature dependence of the critical current density and the effective energy barrier for vortex motion.

A comparison of single crystals and melt-textured Y(123) has been reported by M. Watahiki et al. (ISTEC). The irreversibility fields of the single crystals were greatly enhanced by controlling the oxygen content in the overdoped regime. It is important to increase both the Y(211) precipitate content and the oxygen content simultaneously to get the highest critical current densities.

Bi Cuprates

A preprint by H. Enriquez (Paris) et al. reports the detections of vortex lattice melting in the microwave dissipation at the melting field. They observe a clear onset in the dissipation at the melting field that they identify by a step in the static magnetization. They see the onset of two very different dissipation processes associated with the in-plane and out-of-plane microwave currents.

Josephson and quasiparticle tunneling in SIS junctions of Bi(2212) and Bi(2201) have been studied by point contact tunneling by P. Romano (Argonne) et al. These SIS junctions are generally quite stable, and in the case of Bi(2212), exhibit well-defined simultaneous Josephson and quasiparticle tunnel currents with I_cR_n values between 2 mV and 5 mV. Relatively high conductance Bi(2201) junctions exhibit large Josephson currents with I_cR_n products that are close to the gap voltage.

The incommensurate structure of high-quality Bi(2212) single crystals have been studied using neutron diffraction by P. A. Miles (Sydney) et al. The four-dimensional space group is found to be consistent with N Bbmb/111. They do not find excess oxygen but do observe large modulations in the oxygen associated with the Bi ions in the lattice.

As reported by M. Mamiya (Osaka) et al., high-temperature x-ray powder diffraction and optical microscopy shows that Bi2Sr3Cu2O8 starts to decompose at 910^oC and changes into Bi4Sr8Cu5Ox through a transient state of melting and subsequent solidification. The Bi4Sr8Cu5Ox then decomposes into SrCuO2 at 915^oC with increasing amounts of liquid phase. It is completely liquid above 1010^oC.

Transport and magnetization measurements by R. A. Doyle (Cambridge) et al. have been made on single crystals having plate and prism geometries. Measurements show that the non-linear transport properties do not reflect bulk vortex pinning properties and strongly suggest that the vortex lattice melting is accompanied by vortex decoupling into pancakes.

Ac losses have been studied by H. Eckelmann et al. (Karlsruhe) for tapes with varying geometries. They find that all the loss factors lay within the limits given for an elliptical and strip-like conductors. The difference in loss factor is caused by the filament geometry.

A paper by S. Li (Auckland) et al. reports the fracture behavior of Bi(2223) polycrystals clad with Ag sheets. The results indicate that the randomly oriented crystals cleave and slip along the a-b plane, and rotate to the rolling plane to form an a-b texture microstructure. Details depend on the deformation rate. Under medium and high deformation ratios, a multistep deformation feature has been observed which results from sliding along the a-b plane. With low deformation ratio, the compressive force is not large enough to cause fracture.

J. Jiang et al. (Birmingham) have shown that the phase transformation, microstructure evolution, and critical current density are sensitive to the precursor particle size distribution. Small particle size promotes the formation of Bi(2223) and coarse powder leads to Ca2CuO3 and Ca plumbate. Too fine a powder may cause the formation of large alkaline- earth cuprate grains through the liquid route.

Other Cuprates

A preprint by C. W. Chu et al. (Houston) reports the successful synthesis at high pressure of three distinct high-temperature superconducting phases in the Ba-Ca-Cu-O system with Tc values of 126 K, 118 K, and 107 K. The results show that the local symmetry of the charge reservoir block can dramatically alter the Tc and the chemical stability of the layered cuprates.

A paper by M. Terasawa (Hemeji) et al. reports flux pinning and flux creep in La(214) with splayed columnar defects. For temperatures less that 15 K, the splayed defect samples had a stronger pinning potential than the parallel defect sample. Between 15 K and 30 K, however, the pinning potential for the splayed sample was smaller than for the parallel defect sample.

The local structure of La(214) was studied by Cu K-edge EXAFS by A. Lanzara (Rome) et al. An anomalous temperature dependence of the Debye- Waller factor of the Cu-O (planar) and Cu-La pairs shows competing structural modulations of the perovskite and rock-salt layers. The distorted and undistorted Cu sites are found to be ordered in an array of stripes.

Cu(1234) single crystals with submillimeter size were synthesized at high pressure by K. Tokiwa (Tokyo) et al. using a belt-type anvil machine. The Tc values range from 68 K to 105 K. Au impurities from the Au capsule are found to be an important factor limiting the Tc below the 118 K value for Au-free polycrystals.

A paper by A. V. Lazuta (Petersburg) et al. reports the magnetic susceptibility of oxygen rich La(214) single crystals. In addition to the standard antiferromagnetic response, they find weak ferromagnetism that can be related to the out-of-CuO2-plane staging of the interstitial oxygen.

A new synthesis protocol has been developed by P.V.P.S.S. Sastry et al. (Tallahassee) for the Hg(1223) compounds doped with rare earths, Bi, and Pb. A reduced temperature annealing stage after the high-temperature reaction improves the microstructural characteristics.

Low-energy electronic Raman spectra have been studied for slightly overdoped (La,Sr)214 crystals by X. K. Chen (Simon Frazer) et al. The superconducting energy gap is found to be 7.7 kTc, similar to the optimally doped cuprates. No spectral features could be identified that would allow one to distinguish between compounds having a single CuO2 layer in the unit cell and other compounds having two CuO2 layers in the unit cell.

Borocarbides

A preprint by Z. Q. Peng et al. (Goettingen) reports reentrant behavior in the Dy nickel borocarbides at temperatures below 2 K. The magnetic field dependence of the resistivity with H parallel to [100] exhibits an anomalously large hysteresis and the upper critical field derived from the field decreasing part of the resistivity and shows a peak at 2 K. The authors propose that the interaction between superconductivity and metamagnetism plays a dominent role determining the superconducting properties.

Thin Films

A low temperature anomaly in the penetration depth of Y(123) thin films is reported by H. Walter (Garching) et al. to be evidence for Andreev bound states at the surface. They see an upturn in lambda below 15 K whose onset temperature and its dependence on orientation of the surface are in quantitative agreement with the theory of surface currents that are carried by surface-induced Andreev bound states.

A preprint by D.H.A. Blank et al. (Twente) reports the in-situ diagnostics of ellipsometry and RHEED to study the growth of Y(123) at high pressure. Both pulsed laser and sputter deposition are used to fabricate complex oxide thin films at relatively high oxygen pressures up to 0.5 mBar while simultaneously observing the growth with ellipsometry and RHEED.

Epitaxial growth of Bi-Sr-La-Cu-O films has been reported by Y. Z. Zhang et al. (Beijing). An rf sputtering technique produced zero resistance films with Tc up to 29 K.

A paper by E. K. Hollmann et al. (Petersburg) reports the growth of thick (up to 2.6 micrometers) c-axis Y(123) films. The orientation of the c-axis phase improves with thickness as revealed by x-ray and Rutherford back scattering. Second-phase inclusions and holes seem to play the role of drains for defects and mechanical stress and thus stabilize the c-axis growth.

A double sign reversal of the Hall effect in the mixed state of Y(123) is reported by K. Nakao et al. (Tokyo). Measurements were made in the high current density regime (10^6A/cm^2). The experimental results qualitatively fit the Feigel'man et al. theory.

Grains and Grain Boundaries

A paper by A. M. Saleh (Jerusalem) et al. reports the transport properties of an isolated grain boundary in Bi(2212). They find coexisting Josephson and transport currents with the Jc and Tc depending greatly on heat treatment. The current-voltage characteristics of a single bridge follows a power law, V~(I-I_c)^n where n~~1.2.

A preprint by F. Braun et al. (Karlsruhe) reports an new theory of superconductivity in ultra-small metallic grains. Spin magnetism dominates over orbital magnetism, just as in thin films in a parallel field. In the orbital case, the magnetic-field induced transition to the normal state is first order, but the authors show that for small grains this first order transition is softened by finite size effects. The calculations qualitatively reproduce the magnetic field dependent tunneling spectra for Al grains reported by Ralph, Black, and Tinkham.

The influence of band bending on the normal-state properties of high-Tc superconductors containing grain boundaries is investigated by J. Mannhart et al. (Augsburg). A depletion layer near a grain boundary may be the origin of many of the normal-state transport properties observed in high-Tc thin films.

A paper by S. Ravi (Itanagar) reports a universal behavior for the ac susceptibility of granular Bi-Pb-Sr-Ca-Cu-O. It is shown that both the temperature and magnetic field variation of susceptibility can be determined by a single parameter d that is a function of the penetration field and the amplitude of the ac field.

Overviews

The current status of high-temperature superconductivity is reviewed by M. B. Maple (LaJolla). Recent developments and novel superconductors are briefly described.

A preprint by J. R. Clem (Ames) reviews anisotropy and two-dimensional behavior in the high-temperature superconductors. Emphasis is placed on vortex-lattice melting, flux pinning, flux creep, and critical-current densities.

A paper by D. P. Hampshire (Durham) reviews the factors that control the critical current densities in optimized conductors. Explicit expressions are developed for the dependence of Jc on the upper critical field, Ginzburg-Landau parameter kappa, and a Fermi surface enhancement factor.

Emerging 21st century markets and the outlook for applied superconductivity are reviewed by C. H. Rosner (IGC). HTS products in the medical, electronics, communication, electric power, and industrial- processing fields are discussed and the need for improved cryogenic equipment is presented.

A preprint by C. E. Rossman et al. (Storrs) reviews the problem of spinning magnets levitated over high-temperature superconductors. They discuss how to relate the torque to the moment and the resulting motion in this environment.

Contributed by Douglas K. Finnemore

Contents: Preprints begin on page 5; Coming Events begin on page 12; FYI is on page 12; and some HTCU statistics are shown on page 13.

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.

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.

U. Balachandran, V. Selvamanickam, P. Haldar, M. Lelovic, and N. G. Eror, "Development of Ag-Clad Bi-2223 Superconductors for Electric Power Applications." To be published in the Proc. of the Int. Symp. on Processing and Critical Currents of HTS, Wagga Wagga, Australia, Feb. 2- 4, 1998. Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov.

W. Belzig, C. Bruder, and M. Sigrist, "Quasiclassical Theory of Twin Boundaries in High-Tc Superconductors." Submitted to Phys. Rev. Lett. Institut fuer Theoretische Festkoerperphysik, Universitaet Karlsruhe, D- 76128 Karlsruhe, GERMANY; e-mail wolfgang@tfp.physik.uni-karlsruhe.de; preprint also available at cond-mat@xxx.lanl.gov (#9801107).

Dave H. A. Blank and Horst Rogalla, "In-Situ Diagnostics at High Pressures: Ellipsometric and RHEED Studies of the Growth of YBa2Cu3O7." To be published in the Proc. of the 1997 Fall Meeting of the Mater. Res. Soc., Boston, Mass., Dec. 1-5, 1997. Low Temperature Division, Department of Applied Physics, University of Twente, P.O. Box 217, 7500 AE Enschede, THE NETHERLANDS; e-mail d.h.a.blank@tn.utwente.nl.

Fabian Braun and Jan von Delft, "Superconductivity in Ultrasmall Metallic Grains." Institute fuer Theoretische Festkoerperphysik, Universitaet Karlsruhe, D-76128 Karlsruhe, GERMANY; e-mail fbraun@tfp.physik.uni-karlsruhe.de; preprint also available at cond- mat@xxx.lanl.gov (#9801170). 74.20.Fg; 74.25.Ha; 74.80.Fp.

Mahesh Chandran, "Effect of Linear Defects on the Field-Distribution in Thin Superconductors." To be published in Phys. Rev. B. Low Temperature Physics Group, Centre for Advanced Technology, Indore 452013, INDIA. 74.60.Ge; 74.76.-w; 74.80.-g.

X. K. Chen, J. C. Irwin, H. J. Trodahl, M. Okuya, T. Kimura, and K. Kishio, "Electronic Raman Scattering in Optimally Doped La2-xSrxCuO4." To be published in Physica C (in press). Department of Physics, Simon Fraser University, Burnaby, BC, CANADA V5A 1S6; telephone (604) 291- 3160; telefax (604) 291-3592. Key words: high-temperature superconductor, Raman scattering, d-wave symmetry.

C. W. Chu, Z. L. Du, Y. Y. Xue, Y. Cao, N. L. Wu, I. A. Rusakova, M. Hervieu, and B. Raveau, "The Novel High Temperature Superconducting Ba- Ca-Cu-O System." Preprint #98:017; submitted to the Proc. of the 1997 Conf. on Spectroscopies in Novel Supercond. (SNS'97), Falmouth, Mass., Sept. 14-18, 1997; to be published in J. Phys. Chem. Solids. 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: Ba2Can-1CunO2n+2, CaBa2Can- 1CunO2n+3, structure, space group, cuprate, high-temperature superconductivity.

John R. Clem, "Anisotropy and Two-Dimensional Behavior in the High- Temperature Superconductors." Submitted to the Proc. of the Int. Symp. on Processing and Critical Currents of HTS, Wagga Wagga, Australia, Feb. 2-4, 1998; to be published in Supercond. Sci. & Technol. Ames Laboratory-USDOE and Department of Physics, Iowa State University, Ames, IA 50011-3020; telephone (515) 294-4223; telefax (515) 294-0689; e-mail clem@ameslab.gov.

D. Colson, V. Viallet, A. Forget, S. Poissonnet, L. Schmirgeld-Mignot, J. F. Marucco, and A. Bertinotti, "Gold Substitution in HgBa2Ca2Cu3O8+d Single Crystals." To be published in Physica C (in press). CEA-Saclay, SPEC, F-91191 Gif sur Yvette Cedex, FRANCE; telephone +33 1 6908 7314; telefax +33 1 6908 8786; e-mail colson@spec.saclay.cea.fr. Key words: synthesis, single-crystal growth, magnetic susceptibility. 74.72.Jt; 74.62.Bf; 74.25.Ha.

H. Darhmaoui and J. Jung, "Coherent Josephson Nanostructures and the Dissipation of the Persistent Current in the a-b Planes of Y1Ba2Cu3O7-d Thin Films." To be published in Phys. Rev. B. Department of Physics, University of Alberta, 412 Avadh Bhatia Physics Laboratory, Edmonton, Alberta, CANADA T6G 2J1; J. Jung's telephone (403) 492-5286; telefax (403) 492-0714; e-mail mhen@phys.ualberta.ca.

S. Djordjevic, L. A. de Vaulchier, N. Bontemps, J. P. Vieren, Y. Guldner, S. Moffat, J. Preston, X. Castel, M. Guilloux-Viry, and A. Perrin, "Low Temperature Penetration Depth and the Effect of Quasi- Particle Scattering Measured by Millimeter Wave Transmission in YBa2Cu3O7-d Thin Films." Submitted to Eur. J. Phys. Laboratoire de Physique de la Matiere Condensee, Ecole Normale Superieure, 24 rue Lhomond, F-75231 Paris Cedex 05, FRANCE; telephone +33 1 4432 0000; telefax +33 1 4432 3840; preprint also available at cond- mat@xxx.lanl.gov (#9801244). 07.57.-c; 74.72.-h; 74.76.-w.

R. Dolata and D. Balashov, "Platinum Thin Film Resistors with Cr Under- and Overlayers for Nb/Al2O3/Nb Technology." To be published in Physica C (in press). Physikalisch-Technische Bundesanstalt, Bundesallee 100, D-38116 Braunschweig, GERMANY; telephone +49 531 592 2247; telefax +49 531 592 2295; e-mail ralf.dolata@ptb.de. Key words: thin-film resistors, Nb/Al2O3/Nb technology. 73.61.At; 81.15.Cd; 85.25.Na.

S. X. Dou, R. Zeng, T. P. Beales, and H. K. Liu, "A New Method to Substantially Reduce the Processing Time of Ag/Bi-2223 Tapes." Institute for Superconducting and Electronic Materials, University of Wollongong, NSW 2522, AUSTRALIA; telephone +61 2 4221 5730; telefax +61 2 4221 5731; e-mail shi_dou@uow.edu.au; Web site http://www.uow.edu.au.

R. A. Doyle, T. B. Doyle, E. Zeldov, T. Tamegai, and S. Ooi, "Role of Sample Geometry on Non-Linear Transport Properties of the Vortex Solid in Bi2Sr2CaCu2O8." Interdisciplinary Research Center in Superconductivity, University of Cambridge, Cambridge CB3 0HE, ENGLAND. 74.25.Dw; 74.25.Fy; 74.60.Ge; 74.72.Hs.

H. Eckelmann, M. Daeumling, M. Quilitz, and W. Goldacker, "ac Transport Current Losses of Multifilamentary Bi(2223) Tapes with Varying Filament Geometries." To be published in Physica C (in press). Kernforschungszentrum Karlsruhe, Institut fuer Technische Physik, Postfach 3640, D-76021 Karlsruhe, GERMANY; telephone +49 7247 82 5341; telefax +49 7247 82 5398; e-mail hubert.eckelmann@itp.fzk.de.

R. Eder, W. Hanke, and S. C. Zhang, "From Antiferromagnetism to Superconductivity: Numerical Evidence for SO(5) Symmetry and Superspin Multiplets." Institut fuer Theoretische Physik, Universitaet Wuerzburg, Am Hubland D-97074 Wuerzburg, GERMANY; e-mail eder@physik.uni- wuerzburg.de.

H. Enriquez, Y. De Wilde, N. Bontemps, and T. Tamegai, "Onset of Decoupling at the Melting Field of the Vortex Lattice in Bi2Sr2CaCu2O8+d from Microwave Dissipation." Submitted to Europhys. Lett. Laboratoire de Physique de la Matiere Condensee, Ecole Normale Superieure, 24 rue Lhomond, F-75231 Paris Cedex 05, FRANCE; telephone +33 1 4432 0000; telefax +33 1 4432 3840; preprint also available at cond- mat@xxx.lanl.gov (#9801233). 47.32.Cc; 74.72.-h; 78.70.Gq.

L. Fabrega, B. Martinez, J. Fontcuberta, A. Sin, S. Pinol, and X. Obradors, "Magnetic Irreversibility and Surface Barriers in Grain- Aligned Re-Doped Hg-1223." To be published in Physica C (in press). Institut de Ciencia de Materials de Barcelona, CSIC, Campus de la U.A.B., E-08193 Bellaterra, SPAIN; telephone +34 93 580 1853; telefax +34 93 580 5729. Key words: Hg-based superconductors, Re doping, irreversibility line, surface barriers. 74.72.Gr; 74.25.Ha

J. Ferrer, M. A. Gonzalez-Alvarez, and J. Sanchez-Canizares, "s-s*-d- Wave Superconductor on a Square Lattice and Its BCS Phase Diagram." To be published in Phys. Rev. B. Departamento de Fisica, Facultad de Ciencias, Universidad de Oviedo, E-33007 Oviedo, SPAIN; telephone +34 8 510 2947; telefax +34 8 510 2952; e-mail ferrer@condmat01.geol.uniovi.es; preprint also available at cond- mat@xxx.lanl.gov (#9801109).

Ryoji Funahashi, Ichiro Matsubara, Hiroshi Ohashi, Kazuo Ueno, and Hiroshi Ishikawa, "Preparation Parameters Governing Microstructure and Grain Coupling of Bi2Sr2CaCu2Ox/Ag Tapes Prepared by Partial Melting." To be published in Physica C (in press). Osaka National Research Institute, AIST, Midorigaoka, Ikeda, Osaka 563, JAPAN; telephone +81 727 519541; telefax +81 727 519622; e-mail fune@onri.go.jp. Key words: Bi2Sr2CaCu2Ox/Ag tapes, isothermal partial melting method, preparation parameter, microstructure, grain coupling.

F. Galante, E. Rodriguez, J. Fontcuberta, and X. Obradors, "Vortex Liquid in YBa2Cu3O7:Y2BaCuO5." To be published in Physica C (in press). Contact E. Rodriguez, Laboratorio de Bajas Temperaturas, FCeyN, UBA Pab. I, Ciudad Universitaria, 1428 Buenos Aires, ARGENTINA; telefax +54 1 782 7647. 74.60.Ge.

R. Grosser, A. Martin, M. Niemetz, E. V. Pechen, and W. Schoepe, "Detecting Flux Creep in Superconducting YBa2Cu3O7-d Thin Films Via Damping of the Oscillations of a Levitating Permanent Magnet." Institut fuer Experimentelle und Angewandte Physik, Universitaet Regensburg, D- 93040 Regensburg, GERMANY; M. Niemetz's e-mail michael.niemetz@physik.uni-regensburg.de; preprint also available at cond-mat@xxx.lanl.gov (#9712199).

H. C. Gupta, "Effect of Angular Forces on the Phonons in LuNi2B2C." To be published in Physica C (in press). Department of Physics, Indian Institute of Technology, Hauz Khas, New Delhi-110016, INDIA; telefax +91 11 686 2037.

A. Hahn, S. Hofmann, A. Krause, and P. Seidel, "Tunneling Results on Gap Anisotropy in Niobium." To be published in Physica C (in press). Institut fuer Werkstoffe der Elektrotechnik, Ruhr-Universitaet, D-44780 Bochum, GERMANY; telephone +49 234 700 2511; telefax +49 234 709 4166. Key words: tunneling, energy gap, anisotropic superconductor. 74.50.+r; 74.80.-g; 74.20.Fg; 74.70.-b.

D. P. Hampshire, "A Barrier to Increasing the Critical Current Density of Bulk Untextured Polycrystalline Superconductors in High Magnetic Fields." To be published in Physica C (in press). Superconductivity Group, Department of Physics, Durham University, Durham DH1 3LE, UNITED KINGDOM; telephone +44 191 374 2167; telefax +44 191 374 3749.

E. K. Hollmann, D. A. Plotkin, S. V. Razumov, and A. V. Tumarkin, "The Growth of Thick YBa2Cu3O7-x Films." To be published in Physica C (in press). St. Petersburg Electrotechnical University, 5 Prof. Popova str., 197376 St. Petersburg, RUSSIA.

C. C. Homes, S. Kamal, D. A. Bonn, R. Liang, W. N. Hardy, and B. P. Clayman, "Determination of the Condensate from Optical Techniques in Unconventional Superconductors." To be published in Physica C. Department of Physics, Brookhaven National Laboratory, Building 510B, P.O. Box 5000, Upton, NY 11973-5000; telephone (516) 344-7579; telefax (516) 344-2739; e-mail homes@bnl.gov. Key words: unconventional superconductivity, high-Tc superconductors, anisotropic, far infrared, microwave.

A. Ignatiev, Y. Q. Xu, N. J. Wu, and D. Liu, "Pyroelectric, Ferroelectric and Dielectric Properties of Mn and Sb-Doped PZT Thin Films for Uncooled IR Detectors." Preprint #98:014; to be published in the Proc. of the Fourth Int. Workshop on Oxide Electronics, College Park, Md., Dec. 8-9, 1997. Space Vacuum Epitaxy Center and Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5507; telephone (713) 743-8200; telefax (713) 743-8201; e-mail preprints@www.tcs.uh.edu. Key words: infrared, detector, heterostructure, pyroelectrics, thin film.

E. S. Itskevich and E. V. Zhasinas, "Interlayer Effects in Hg High-Tc Cuprates Under High Pressure." To be published in Physica C (in press). Institute for High Pressure Physics, 142092 Troitsk, Moscow Region, RUSSIA; telefax +7 95 3340589; e-mail itskev@ns.hppi.troitsk.ru.

J. Jiang and J. S. Abell, "Effects of Precursor Powder Particle Size on Critical Current Density and Microstructure of Bi-2223/Ag Tapes." To be published in Physica C (in press). School of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT, UNITED KINGDOM; telefax +44 121 414 5232; e-mail j.jiang.l@bham.ac.uk. Key words: critical current density, superconducting tape, microstructure. 74.72.Hs; 74.62.Bf; 85.25.Kx; 81.40.-z.

U. Kalberkamp, U. Matzander, K.-D. Husemann, G. Panaitow, E. Zimmermann, and Y. Zhang, "HTS rf-SQUID Applications to Geophysical Exploration Methods." To be published in Appl. Supercond. Contact U. Matzander, Institut fuer Angewandte Berlin, Technische Universitat Berlin, Ackerstrasse 71-76, D-13355 Berlin, GERMANY.

Yong-Jihn Kim, "Strong-Coupling Theory of Impure Superconductors: Correspondence with Weak-Coupling Theory." Submitted to Phys. Rev. B. Department of Physics, Korea Advanced Institute of Science and Technology, Taejon 305-701, KOREA; e-mail yjkim@taesan.kaist.ac.kr; preprint also available at cond-mat@xxx.lanl.gov (#9712295). 74.20.-z; 74.40.+k.

Yong-Jihn Kim and K. J. Chang, "Impurity Doping Effect in High Tc Superconductors." Submitted to Phys. Rev. B. Department of Physics, Korea Advanced Institute of Science and Technology, Taejon 305-701, KOREA; e-mail yjkim@taesan.kaist.ac.kr; preprint also available at cond- mat@xxx.lanl.gov (#9801071). 74.20.-z; 74.40.+k.

Wolfgang T. Koenig and Gerhard Gritzner, "Microstructure and Properties of Textured Bulk Phase Tl(Bi)-1223 Superconductors." To be published in Physica C (in press). Institut fuer Chemische Technologie Anorganischer Stoffe, Johannes Kepler Universitaet, A-4040 Linz, AUSTRIA; telephone +43 732 246 8702; telefax +43 732 246 8905; e-mail wolfgang.koenig@ictas.uni-linz.ac.at.

Gertjan Koster, Guus J.H.M. Rijnders, Dave H. A. Blank, and Horst Rogalla, "In Situ Initial Growth Studies of (Sr,Ca)CuO2 on SrTiO3 by High Pressure RHEED." To be published in the Proc. of the 1997 Fall Meeting of the Mater. Res. Soc., Boston, Mass., Dec. 1-5, 1997. Low Temperature Division, Department of Applied Physics, University of Twente, P.O. Box 217, 7500 AE Enschede, THE NETHERLANDS; Dave H. A. Blank's e-mail d.h.a.blank@tn.utwente.nl.

V. M. Krasnov and V. V. Ryazanov, "Comparison of the Pinning and the Bulk Currents in the Critical State of Type-II Superconductor." To be published in Physica C. Department of Physics, Chalmers University of Technology, S-41296 Goeteborg, SWEDEN; telephone +46 31 772 3397; telefax +46 31 772 3471; e-mail krasnov@fy.chalmers.se. 74.60.Jg; 74.60.Ge; 74.60.Ec.

Edwin Langmann, Jack Lidmar, Manfred Salmhofer, and Mats Wallin, "Mean Field Analysis of a Model for Superconductivity in an Anti-Ferromagnetic Background." To be published in Physica C (in press). Contact Jack Lidmar, Theoretical Physics, Royal Institute of Technology, S-100 44 Stockholm, SWEDEN; telefax +46 8 200430; e-mail jack@theophys.kth.se. 21.60.Jz; 74.72.-h; 74.70.Tx.

A. Lanzara, N. L. Saini, A. Bianconi, F. C. Chou, and D. C. Johnston, "Anomalous Structural Modulations in La2CuO4.1." To be published in Physica C (in press). Contact A. Bianconi, Dipartimento di Fisica, Universita di Roma 'La Sapienza', P. Aldo Moro 5, I-00185 Roma, ITALY; telephone +39 6 499 14405; telefax +39 6 495 7697; e-mail antonio.bianconi@roma1.infn.it. 74.72.Dn; 61.10.Ht; 78.70.Dm.

A. V. Lazuta, V. A. Ryzhov, I. I. Larionov, and T. I. Arbuzova, "Second- Order Uniform Dynamic Susceptibility of Lightly Oxygenated La2CuO4+x Single Crystals and Peculiarity of Their Magnetic Properties at Phase Separation." To be published in Physica C (in press). Petersburg Nuclear Physics Institute, Russian Academy of Science, 188350 Gatchina, St. Petersburg District, RUSSIA; telephone +7 812 348 9590; telefax +7 812 713 1963; e-mail lazuta@thd.pnpi.spb.ru. Key words: critical phenomena, Cu-O planes, ac magnetic susceptibility, oxygen stoichiometry, phase separation.

S. Li, W. Gao, Q. Y. Hu, H. K. Liu, and S. X. Dou, "The Fracture Behavior of (Bi,Pb)2Sr2Ca2Cu3O10+x Polycrystals Clad with Silver Sheets." To be published in Physica C (in press). Contact W. Gao, Department of Chemical and Materials Engineering, University of Auckland, Auckland, NEW ZEALAND; telephone +64 9 373 7599; telefax +64 9 373 7463; e-mail w.gao@auckland.ac.nz.

Mikito Mamiya, Takuya Suzuki, Masashi Hasegawa, and Humihiko Takei, "In Situ Observation of the Thermal Stability Field of Bi2Sr3Cu2O8." To be published in Physica C (in press). Graduate School of Science, Osaka University, 1-16 Machikaneyama, Toyonaka-shi, Osaka 560, JAPAN; telephone +81 6 850 5795; telefax +81 6 850 5817; e-mail mamiya@ess.sci.osaka-u.ac.jp. Key words: Bi2Sr3Cu2O8, phase diagram, thermal stability, in-situ observation, Bi-Sr-Cu-O system.

J. Mannhart and H. Hilgenkamp, "Possible Influence of Band Bending on the Normal State Properties of Grain Boundaries in High-Tc Superconductors." Experimentalphysik VI, Center for Electronic Correlations and Magnetism, Universitaet Augsburg, Universitaetsstr. 1, D-86135 Augsburg, GERMANY; telephone +49 821 598 3650; telefax +49 821 598 3652; e-mail jochen.mannhart@physik.uni-augsburg.de. Key words: high-temperature superconductivity, Josephson junctions, grain boundaries.

M. Brian Maple, "High Temperature Superconductivity." To be published in J. Magn. & Magn. Mater. Department of Physics-0319, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0319; telephone (619) 534-3968; telefax (619) 534-1241; e-mail mbmaple@ucsd.edu. Key words: superconductivity, high-Tc superconductors, ceramic, electronic correlations, order parameter.

I. Meinel, D. Grundler, S. Bargstaedt-Franke, Ch. Heyn, and D. Heitmann, "SQUID-Susceptometry up to 10 Tesla: An Improved Method for Magnetization Studies on a Two-Dimensional Electron System." To be published in Appl. Supercond. Institut fuer Angewandte Physik und Zentrum fuer Mikrostrukturforschung, Universitaet Hamburg, Jungiusstrasse 11, D-20355 Hamburg, GERMANY; telephone +49 40 4123 6487; telefax +49 40 4123 6332; e-mail meinel@physnet.uni-hamburg.de.

P. N. Mikheenko, J. Horvat, and S. X. Dou, "Diamagnetic Transition of Bi2223/Ag Tapes: The Role of Low-Number Stacks of Superconducting Layers." To be published in Physica C. Centre for Superconducting and Electronic Materials, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, AUSTRALIA; telephone +61 42 21 5726; telefax +61 42 21 5731; e-mail mikhe@uow.edu.au. Key words: ac susceptibility, Cu- O planes, critical current density, fluctuation effects, interlayer pairing.

P. A. Miles, S. J. Kennedy, G. J. McIntyre, G. D. Gu, G. J. Russell, and N. Koshizuka, "Refinement of the Incommensurate Structure of High Quality Bi-2212 Single Crystals from a Neutron Diffraction Study." To be published in Physica C (in press). Contact G. J. Russell, Advanced Electronic Materials Group, School of Physics, University of NSW, Sydney NSW 2052, AUSTRALIA; telephone +61 2 9385 4542; telefax +61 2 9385 6060; e-mail g.russell@unsw.edu.au.

T. Mimura, I. Terasaki, K. Tomimoto, S. Tajima, M. Nakamura, and Y. Shiohara, "Unusual Resistivity Broadening in the Mixed State of NdBa2Cu3O7-d Crystals Grown by a Crystal-Pulling Technique." To be published in Physica C. 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.

Kazuya Mori, Toru Ishigaki, and Akira Sakai, "Carrier Concentration and Phonon Anomaly Above Tc in the YBa2Cu4O8 System." To be published in Physica C (in press). Contact Toru Ishigaki, Department of Materials Science and Engineering, Muroran Institute of Technology, Muroran 050, JAPAN; telefax +81 143 47 3195; e-mail ishigaki@oyna.cc.muroran- it.ac.jp. Key words: Raman scattering, phonon anomaly above Tc, carrier density, YBa2Cu4O8 system.

Sharmila M. Mukhopadhyay and Chao Wei, "Interaction of Bromine with Y1Ba2Cu3O7-x: Its Role as a Dopant and an Etchant." To be published in Physica C (in press). Mechanical and Materials Engineering, Wright State University, Dayton, OH 45435; telephone (937) 775-5092; telefax (937) 775-5009.

K. Nakao, K. Hayashi, T. Utagawa, Y. Enomoto, and N. Koshizuka, "Double Sign Reversal of the Hall Effect in the Mixed State of YBa2Cu3Ox." To be published in Phys. Rev. B. 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.

E. P. Nakhmedov, OE. Cakroglu, M. Huener, and K. Al-Shibani, "Charging Effects on the Critical Temperature of the Josephson-Coupled Layered Superconductors." To be published in Physica C (in press). Faculty of Science and Letters, Department of Physics, Istanbul Technical University, Maslak, 80626 Istanbul, TURKEY. 74.40.+k; 74.80.Dm; 74.60.- w; 74.20.De; 74.60.Ec.

Yusuke Niiori, Yasuji Yamada, and Izumi Hirabayashi, "Low Temperature LPE Growth of YBa2Cu3O6+x Thick Film on Silver Substrate Using Silver Saturated Ba-Cu-O-F Flux." To be published in Physica C (in press). Superconductivity Research Laboratory, International Superconductivity Technology Center (ISTEC), 2-4-1 Mutsuno Atsuta-ku, Nagoya 456, JAPAN; telephone +81 52 8714002; telefax +81 52 8714090; e-mail niiori@istec.or.jp. Key words: YBa2Cu3O6+x, liquid-phase epitaxy, silver, pulsed-laser deposition, thick film. 74.72.Bk; 81.15.Lm; 81.30.-t.

C. J. Olson, C. Reichhardt, and Franco Nori, "Fractal Networks, Braiding Channels, and Voltage Noise in Intermittently Flowing Rivers of Quantized Magnetic Flux." To be published in Phys. Rev. Lett. Department of Physics, University of Michigan, Ann Arbor, MI 48109-1120; telephone (734) 647-5552; e-mail colson@umich.edu; preprint also available at cond-mat@xxx.lanl.gov (#9801128). 74.60.Ge; 62.20.Fe.

J. Paaske and D. V. Khveshchenko, "Intrinsic Temperature Dependences of Transport Coefficients Within the Hot-Spot Model for Normal State YBCO." Orsted Laboratory, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen O, DENMARK; e-mail paaske@alf.nbi.dk; preprint also available at cond-mat@xxx.lanl.gov (#9801126).

Alexey Pan, Michael Ziese, Roland Hoehne, Pablo Esquinazi, Silvia Knappe, and Hans Koch, "Surface Superconductivity and Matching Effect in a Niobium Thin Film." Submitted to Physica C. Department of Superconductivity and Magnetism, Universitaet Leipzig, Linnestr. 5, D- 04103 Leipzig, GERMANY; e-mail pan@physik.uni-leipzig.de.

Z. Q. Peng, K. Krug, and K. Winzer, "Large Hysteresis Effect and Reentrant Behavior in DyNi2B2C at Temperatures T < 2 K." To be published in Phys. Rev. B. I. Physikalisches Institut, Georg-August- Universitaet Goettingen, Bunsenstrasse 9, D-37073 Goettingen, GERMANY; e-mail pzhiqia@gwde.de. 74.72.Ny; 74.25.Ha; 74.25.Fy; 74.25.Dw.

F. Prado, A. Caneiro, and A. Serquis, "High Temperature Thermodynamic Properties, Orthorhombic/Tetragonal Transition and Phase Stability of GdBa2Cu3Oy and Related R123 Compounds." To be published in Physica C (in press). Contact A. Caneiro, Centro Atomico Bariloche, Comision Nacional de Energia Atomica, 8400 San Carlos de Bariloche, ARGENTINA; telephone +54 944 45274; telefax +54 944 45299; e-mail caneiro@cab.cnea.edu.ar. Key words: RBa2Cu3Oy, oxygen stoichiometry, O/T transition. 74.25.Bt; 74.62.-c; 74.62.Dh.

Amit Pratap, Ajay, and R. S. Tripathi, "Spin Wave Contribution to the Thermal Expansion of High-Tc Cuprate Superconductors." To be published in Physica C (in press). Department of Physics, G. B. Pant University of Agriculture and Technology, Pantnagar (U.P.) 263 145, INDIA.

S. Ravi, "Universal Behavior of ac Susceptibility of Granular (Bi1.2Pb0.3)Sr1.5Ca2Cu3Oy Superconductors." To be published in Physica C (in press). Department of Physics, North Eastern Regional Institute of Science and Technology, Nirjuli 791 109, Itanagar, INDIA; telephone +91 3 604 7401; telefax +91 3 604 4307. Key words: Bi-Sr-Ca-Cu-O superconductors, ac susceptibility, universal behavior.

C. Reichhardt, C. J. Olson, and Franco Nori, "Commensurate and Incommensurate Vortex States in Superconductors with Periodic Pinning Arrays." To be published in Phys. Rev. B. Department of Physics, University of Michigan, Ann Arbor, MI 48109-1120; C. J. Olson's telephone (734) 647-5552; e-mail colson@umich.edu; preprint also available at cond-mat@xxx.lanl.gov (#9801020). 74.60.Ge.

Guus J.H.M. Rijnders, Gertjan Koster, Dave H.A. Blank, and Horst Rogalla, "In-Situ Monitoring During PLD of Complex Oxides Using RHEED at High Oxygen Pressure." To be published in the Proc. of the 1997 Fall Meeting of the Mater. Res. Soc., Boston, Mass., Dec. 1-5, 1997. Low Temperature Division, Department of Applied Physics, University of Twente, P.O. Box 217, 7500 AE Enschede, THE NETHERLANDS; Dave H.A. Blank's e-mail d.h.a.blank@tn.utwente.nl.

P. Romano, June Chen, and John Zasadzinski, "Josephson and Quasiparticle Tunneling in SIS Junctions of Bi2Sr2CaCu2O8 and Bi2Sr2CuO6." To be published in Physica C (in press). Dipartimento di Fisica, Universita di Salerno, I-84081 Baronissi, ITALY.

Carl H. Rosner, "Emerging 21st Century Markets and Outlook for Applied Superconducting Products." Presented at the Int. Cryogenic Eng. Conf. and the Int. Cryogenic Mater. Conf. (Joint CEC/ICMC 1997 Conf.), Portland, Oreg., July 27-Aug. 1, 1997. Intermagnetics General Corporation, P.O. Box 461, Latham NY 12110-0461; telephone (518) 782- 1122; telefax (518) 783-2601.

Court E. Rossman and Joseph I. Budnick, "Precession of Spinning Magnets Levitated Over High-Temperature Superconductors." To be published in Physica C (in press). Unit 15C, 55 Littleton Road, Ayer, MA 01432; telephone (508) 772-4885; e-mail rochross@aol.com. Key words: levitation, precession, torques, ac susceptibility of superconductors, critical current density, granular superconductivity, flux creep.

T. Sakai and Y. Takahashi, "Pseudo-Gap Behavior in Dynamical Properties of High-Tc Cuprates." Faculty of Science, Himeji Institute of Technology, 1479-1 Kanaji, Kamigori, Ako-gun, Hyogo 678-12, JAPAN; telephone +81 7915 8 0150; telefax +81 7915 8 0132; e-mail sakai@sci.himiji-tech.ac.jp; preprint also available at cond- mat@xxx.lanl.gov (#9712104). 75.10.Lp; 75.40.Gb; 75.50.Ee.

A. M. Saleh, G. Schindler, C. Sarma, D. G. Haase, C. C. Koch, and A. I. Kingon, "Isolation Techniques and Electrical Characterization of Single Grain Boundaries of Bi2Sr2CaCu2Od High-Temperature Superconductor." To be published in Physica C (in press). College of Science and Technology, Al-Quds University, Abu Deis, P.O. Box 20002, Jerusalem, West Bank, ISRAEL; telefax +972 2 746960; e-mail saleh@alquds.edu.

M. I. Salkola and J. R. Schrieffer, "Inhomogeneous States of Nonequilibrium Superconductors: Quasiparticle Bags and Antiphase Domain Walls." Theoretical Division, T-11, Mail Stop B262, Los Alamos National Laboratory, Los Alamos, NM 87545; telephone (505) 665-0416; telefax (505) 665-4063; e-mail msa@viking.lanl.gov; preprint also available at cond-mat@xxx.lanl.gov (#9801084). 74.80.-g; 74.20.-z; 74.25.Jb; 74.25.Gz.

V. Sandu, S. Popa, J. Jaklovszky, and Elena Cimpoiasu, "Nonmonotonous Variation of the Superconducting Parameters of Neutron Irradiated Li- Doped YBa2Cu3O7-x." To be published in J. Supercond. Department of Low Temperature Physics and Superconductivity - L120, National Institute of Material Physics, P.O. MG-7, Bucharest-Magurele R-76900 ROMANIA; telephone +40 1 780 34 69, ext.1876; telefax +40 1 423 1700; e-mail vsandu@alpha1.infim.ro or vsandu@roifa.ifa.ro. Key words: YBa2Cu3O7-x, Li-doped superconductors, critical temperature, critical currents density, neutron irradiation, Van Hove singularity.

P.V.P.S.S. Sastry, D. C. Knoll, and J. Schwartz, "Synthesis and Processing of Doped Hg1Ba2Ca2Cu3Oy Superconductors." To be published in the Proc. of the 8th U.S.-Japan Workshop on High Temp. Supercond., Tallahassee, Fla., Dec. 8-10, 1997. National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310; telephone (850) 644-1447; telefax (850) 644-0867; e-mail pamidi@magnet.fsu.edu.

Sergei A. Sergeenkov, "On Electrostriction of a Granular Superconductor." To be published in Solid State Commun. Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, RUSSIA; e-mail ssa@thsun1.jinr.dubna.su.

P. V. Shevchenko and O. P. Sushkov, "The Role of g-Wave Pairing and Josephson Tunneling in High-Tc Cuprate Superconductors." To be published in Physica C (in press). School of Physics, University of New South Wales, Sydney 2052, AUSTRALIA; telephone +61 2 9385 6132; telefax +61 2 9385 6060; e-mail pavel@newt.phys.unsw.edu.au. Key words: Josephson tunneling in two condensate cuprate superconductors. 74.50.+r; 74.90.+n.

Hiroshi Shimahara, "Structure of the Fulde-Ferrell-Larkin-Ovchinnikov State in Two-Dimensional Superconductors." Faculty of Science, Hiroshima University, Higashi-Hiroshima 739, JAPAN; e-mail simahara@minerva.ias.hiroshima-u.ac.jp; preprint also available at cond- mat@xxx.lanl.gov (#9711017). Key words: Fulde-Ferrell-Larkin- Ovchinnikov state, FFLO state, nonuniform superconductivity, organic superconductor, two-dimensional system, Pauli paramagnetic limit, upper critical field.

B. Shinozaki, K. Omata, K. Yamada, T. Kawaguti, Y. Fujimori, and T. Aomine, "Electrical Transport and Superconducting Properties of Thin Tin-Copper Films." To be published in Physica C (in press). Department of Physics, Kyushu University, Ropponmatsu, 4-2-1 Ropponmatsu, Chuo-ku, Fukuoka 810, JAPAN; telephone +81 92 726 4737; telefax +81 92 726 4737; e-mail shinoza@rc.kyushu-u.ac.jp. Key words: disordered superconducting film, pair breaking parameter, electron-phonon inelastic scattering rate, electron mean free path.

Sandeep Singh, "Suppression of Superconductivity in Sm and Co Substituted Bi2Sr2Ca1Cu2O8+d System." To be published in Physica C (in press). Surface Physics Group, National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012, INDIA. Key words: x-ray diffraction, transition temperature, doping, resistivity, magnetoresistance, metal- insulator transition.

K. P. Sinha, "The Fermion-Lochon Model and the Symmetry of the Order Parameter in Cuprate Superconductors." Department of Physics, Indian Institute of Science, Bangalore 560 012, INDIA.

D. Rama Sita and R. Singh, "Thermoelectric Power Studies on Bi2Sr2Ca1- xPrxCu2Oy System." To be published in Physica C (in press). Contact R. Singh, School of Physics, University of Hyderabad, Central University, P.O. Hyderabad 500 046, INDIA; telephone +91 40 3010500; telefax +91 40 301 0145; e-mail rtssp@uohyd.ernet.in.

Victor K. Souw, Shi Li, M. McElfresh, R. Prozorov, and Y. Yeshurun, "Reversible Magnetization in Strong-Pinning YBa2Cu3O7-d Thin Films." Department of Physics, Purdue University, West Lafayette, IN 47907. 74.60.-w; 74.25.Ha; 74.60.Ge.

E. Straube, D. Hohlwein, and F. Kubanek, "The Ortho-II Superstructure of YBa2Cu3O6.5: Temperature Behavior, Oxygen Ordering and Tc." To be published in Physica C (in press). Contact D. Hohlwein, Institut fuer Kristallographie, Universitaet Tuebingen and Hahn-Meitner-Institut, Glienickerstrasse 100, Postfach 390128, D-14109 Berlin, GERMANY; telephone +49 30 8062 2708; telefax +49 30 8062 2999. Key words: YBa2Cu3O6.5, x-ray diffraction, high-Tc superconductor, oxygen ordering, transition temperature.

Xuefeng Sun, Wenbin Wu, Li Yang, Wentao Yu, Ping Yang, Guien Zhou, and Xiao-Guang Li, "Study on the Structure of a New Single Crystal Bi2Sr1.5Pr2.5Cu2Oy." To be published in Physica C (in press). Structure Research Laboratory, University of Science and Technology of China, Academia Sinica, Hefei 230026, PEOPLE'S REPUBLIC OF CHINA; e-mail lixg@email.sc.ustc.edu.cn. Key words: Bi2Sr1.5Pr2.5Cu2Oy, crystal structure, modulation.

Kimihito Tagaya, Jyunji Kawabata, Yoshihiro Taniguchi, Hiroyuki Sasakura, and Shin-ichi Kikkawa, "Magnetic Properties of (Pb,Cu)1(Sr,Gd)2(La,Gd)2Cu2Oz." To be published in Physica C (in press). Department of Materials Science, Osaka Prefecture University, Sakai, Osaka 593, JAPAN; telephone +81 722 521161; telefax +81 722 552981; e-mail tagaya@cias.osakafu-u.ac.jp. Key words: weak superconductivity, (Pb,Cu)-1222, weak ferromagnetism, dc magnetization, electron spin resonance.

B. A. Tent, D. Qu, and Donglu Shi, "Angle Dependence of Levitation Force in a YBa2Cu3Ox Sphere." Submitted to Phys. Rev. B. Department of Materials Science and Engineering, University of Cincinnati, Cincinnati, OH 45211.

M. Terasawa, N. Takezawa, K. Fukushima, T. Mitamura, X. Fan, H. Tsubakino, T. Kohara, K. Ueda, Y. Awaya, T. Kambara, M. Matsuda, and G. Tatara, "Flux Pinning and Flux Creep in La2-xSrxCuO4 with Splayed Columnar Defects." To be published in Physica C (in press). Himeji Institute of Technology, 2167 Shosha, Himeji 671-22, JAPAN. Key words: La2-xSrxCuO4, critical current density, flux creep, heavy-ion irradiation, columnar defects.

I. Tifrea, I. Grosu, and M. Crisan, "Critical Temperature and Coulomb Repulsion in a Non-Fermi Liquid Superconductor." To be published in Physica C (in press). Contact M. Crisan, Department of Theoretical Physics, University of Cluj, 3400 Cluj, ROMANIA; +40 64 191 906; e-mail mcrisan@phys.ubbcluj.ro.

Shinjiro Tochihara, Hiroshi Yasuoka, and Hiromasa Mazaki, "Effect of Surface Barriers and Lower Critical Fields to Magnetization of Type-II Superconductors." To be published in Physica C (in press). Contact Hiromasa Mazaki, Department of Mathematics and Physics, National Defense Academy, Yokosuka 239, JAPAN; telephone +81 468 413810; telefax +81 468 445902; e-mail mazaki@cmr4w1.cc.nda.jp.

K. Tokiwa, Y. Tanaka, A. Iyo, Y. Tsubaki, K. Tanaka, J. Akimoto, Y. Oosawa, N. Terada, M. Hirabayashi, M. Tokumoto, S. K. Agarwal, T. Tsukamoto, and H. Ihara, "High Pressure Synthesis and Characterization of Single Crystals of CuBa2Ca3Cu4Oy Superconductor." To be published in Physica C. Contact Y. Tanaka, Superconducting Materials Laboratory, Material Science Division, Electrotechnical Laboratory, 305-8568 Tsukuba, Ibaraki, JAPAN; telefax +81 298 54 5447; e-mail y.tanaka@etl.go.jp. Key words: Cu-1234 single crystal, high-pressure synthesis, in-plane and out-of-plane resistivity, effect of Au.

P. Verges, K. Fischer, A. Huetten, and G. Fuchs, "Pancake Coils Made from Bi-2223/Ag Tapes." To be published in Cryogenics. Institut fuer Festkoerper- und Werkstofforschung Dresden, P.O. Box 270016, D-01171 Dresden, GERMANY; telephone +49 351 4659 532; telefax +49 351 4659 537; e-mail p.verges@ifw-dresden.de. Key words: superconducting magnet, Bi- 2223/Ag, critical current.

V. Vinokur, B. Khaykovich, E. Zeldov, M. Konczykowski, R. A. Doyle, and P. H. Kes, "Lindemann Criterion and Vortex-Matter Phase Transitions in High-Temperature Superconductors." To be published in Physica C (in press). Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telephone (630) 252-3765; telefax (630) 252-7777.

H. Walter, W. Prusseit, R. Semerad, H. Kinder, W. Assmann, H. Huber, H. Burkhardt, D. Rainer, and J. A. Sauls, "Low-Temperature Anomaly in the Penetration Depth of YBa2Cu3O7 Films: Evidence for Andreev Bound States at Surfaces." Submitted to Phys. Rev. Lett. Physik Department E10, Technische Universitaet Muenchen, James-Franck Str. 1, D-85747 Garching, GERMANY; W. Prusseit's telephone +49 89 2891 2407; telefax +49 89 2891 2414; e-mail prusseit@physik.tu-muenchen.de.

M. Watahiki, W. J. Jang, N. Sakai, and M. Murakami, "Comparative Study of Magnetic Properties Between Melt-Textured and Single Crystalline Y- Ba-Cu-O." To be published in Physica C (in press). Superconductivity Research Laboratory, International Superconductivity Technology Center (ISTEC), 1-16-25 Shibaura, Minato-ku, Tokyo 105, JAPAN; e-mail watahiki@istec.or.jp. Key words: YBa2Cu3Oy, crystal pulling, melt process, Y2BaCuO5, critical current.

Y. Z. Zhang, L. Li, D. G. Yang, B. R. Zhao, H. Chen, C. Dong, H. J. Tao, H. T. Yang, S. L. Jia, B. Yin, J. W. Li, and Z. X. Zhao, "Epitaxial Growth of Bi2Sr2-xLaxCuO6+d Thin Films by rf-Magnetron Sputtering." To be published in Physica C (in press). National Laboratory for Superconductivity, Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, PEOPLE'S REPUBLIC OF CHINA. 74.62.Dh; 74.72.Hs; 74.76.Bz; 68.90.+g.

COMING EVENTS (An * indicates a previously listed event.)

*April 29 - May 2, 1998: 15th Annual International Convention: The High Speed Ground Transportation Association, Chicago Westin Hotel, Chicago, Illinois. The three-day program will include technological updates; environmental issues; federal, state, and local government policy discussions; international project developments; project management tools and techniques; state and regional updates; and financing alternatives. Contact HSGTA, 1010 Massachusetts Avenue, Suite 110, Washington, DC 20001; phone (202) 789-8107; fax (202) 789-8109.

June 29 - July 10, 1998: 1998 Summer Course on Superconducting Materials -- Advances in Technology and Applications, CNR Conference Centre, Bologna, Italy. Will focus on both HTS and LTS superconducting materials. Fundamental aspects, theory, and advances in materials synthesis, processing, and properties will be featured as well as current developments in superconducting component and devices. Particular emphasis will be placed on existing and potential applications of HTS superconductors. In addition to the official lectures, several seminars will be held by invited scientists. Director of Summer Course: K. Kitazawa (University of Tokyo, Japan). Course is open to all participants, however, attendance will be limited to about 70 students. Topics include HTS materials history and perspectives; chemical and structural aspects of superconducting phases; new classes of superconductors; physical properties and mechanisms of superconducting materials; dissipative properties and ac losses; synthesis methodologies; bulk materials and thick films; thin films and multilayers; tapes and wires; relationships between process parameters and functional properties; main characterization techniques for materials and performances; medical applications; large-scale applications such as energy production, magnets, motors, magnetic energy storage, accelerator technology, and space applications; and small-scale applications including active (microwave resonators and filters) and passive devices (Josephson junctions and circuits, detectors, and sensors). For further information, contact Anna Tampieri, Scientific secretary, IRTEC-CNR, via Granarolo,64, I-48018 Faenza, Italy; telephone +39 546 699 757; telefax +39 546 46 381; e-mail superconductors@irtec1.irtec.bo.cnr.it; Web site http://area.bo.cnr.it/ldavinci.

Aug. 25 - 29, 1998: 6th International Conference on Path-Integrals from peV to TeV: 50 Years from Feynman's Paper, Florence, Italy. Sixth in the series. Purpose is to enhance interchange among scientists using functional integration as an essential tool for physical computations (ranging from peV to TeV and beyond) in an informal setting to exchange opinions, discuss problems, and disseminate new ideas. The 1998 Conference is also aimed at being a celebration of the 50th anniversary of Feynman's paper, the milestone of path integration. Will consist of key lectures and plenary contributions. For information, contact Ruggero Vaia, IEQ-CNR, via Panciatichi 56/30, I-50127 Firenze, Italy; telephone +39 55 416128, ext 50; telefax +39 55 414612; e-mail vaia@ieq.fi.cnr.it; Web site http://www.area.fi.cnr.it/pi98/.

May 30 - June 3, 1999: 10th International Symposium on Intercalation Compounds (ISIC 10), Okazaki, Japan. Tenth in the series. Will focus on basic ideas in both the physics and chemistry of intercalation materials such as graphite, fullerenes, carbon nanotubes, chalcogenides, oxides, clays, zeolites, and other related materials. Topics to be covered: new intercalation compounds and new synthetic routes; thermodynamics, kinetics, and reaction mechanisms; structure and lattice dynamics; phase transitions; electronic properties, charge transfer, and band structures; transport properties and superconductivity; magnetic properties; electrochemical properties; intercalation electrodes for advanced batteries; and other present and potential applications. Scientific program will consist of plenary lectures as well as oral and poster sessions. Proceedings to be published as a special issue of Molecular Crystals and Liquid Crystals. Abstract deadline, December 15, 1998. For further information, contact Toshiaki Enoki, ISIC 10, Department of Chemistry, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-.8551, Japan; telefax +81 3-5734 2242; e-mail isic@chem.titech.ac.jp; Web site http://www.chem.titech.ac.jp/~isic/.

FYI (High-Tc Update takes no responsibility for want ads listed in this section.)

Position open: An EPSRC-funded three-year Ph.D. Project Studentship will become available in April 1998. Permanent residents of the UK or the EC are eligible to apply. The project will involve experimental investigation (using transport and magnetization techniques) of vortex dynamics, critical currents, and pinning in high-temperature superconductors. Interested candidates should send a curriculum vitae to Dr. Richard Doyle, IRC in Superconductivity, University of Cambridge, Cambridge CB3 0HE, United Kingdom; e-mail rad1005@hermes.cam.ac.uk.

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, #4, February 15, 1998.