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, ONR, NSF, EPRI, and other agencies, organizations, and individuals.

The High-Tc Update web page is located at the URL http://www.iitap.iastate.edu/htcu/htcu.html

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:

Phonons

By accounting for the coupling between c-axis phonons and Josephson oscillations, F. Forsthofer (Regensburg) et al. quantitatively explain recently reported subgap structures observed in the c-axis current- voltage characteristics of intrinsic Josephson junctions in the high-Tc superconductors Tl2Ba2Ca2Cu3O10+d (Tl-2223) and Bi2Sr2CaCu2O8+d (Bi- 2212). In this model, c-axis lattice vibrations between adjacent superconducting multilayers are excited by the Josephson oscillations in resistive junctions. The voltages of the lowest structures correspond well to the frequencies of longitudinal c-axis phonons with large oscillator strength in the two materials, providing a new measurement technique for this quantity.

A preprint by R. S. Gonnelli (Torino) et al. discusses the limitations of the standard program for inverting the Eliashberg equations to determine the electron-phonon spectral function alpha^2(omega)F(omega) and the Coulomb pseudopotential mu* from tunneling measurements in high- Tc superconductors. Rather than neglecting the energy dependence of the normal-state density of states N_n(omega), as is usually done for conventional superconductors, the authors introduced into the Eliashberg equations several models for N_n(omega) with enhanced values near the Fermi level. The authors applied their new program to determine alpha^2(omega)F(omega) and mu* from their tunneling data on Bi2Sr2CaCu2O8+d (Bi-2212) single-crystal break junctions with Tc = 93 K. One model for N_n(omega) yielded lambda = 3.34, mu* = 0.93 x 10^[-2], Tc = 93.6 K, and features in alpha^2(omega)F(omega) that provide a reasonable match to the generalized phonon density of states G(omega).

RNi2B2C

Scanning-tunneling-microscopy (STM) measurements at 4.2 K by Y. De Wilde (Argonne) et al. on the (001) surface of a superconducting (Tc = 15.8 K) LuNi2B2C borocarbide single crystal have revealed that the vortex lattice in magnetic fields of 1.5 T and 0.375 T is square, with an orientation of 45 degrees with respect to the crystalline a axis. In zero field, the conductance versus voltage characteristics recorded at various locations on the sample reproducibly yield a gap parameter of Delta = 2.2 meV and the gap ratio 2Delta/k_BTc = 3.2+-0.1. The authors explain the results by adding higher-order derivative terms to the Ginzburg-Landau expansion, and they correlate the square vortex lattice with an in-plane upper-critical-field anisotropy H_[c2](45 degrees)/H_[c2](0) = 0.92.

High-quality c-axis-oriented thin films of the superconductor YNi2B2C have been obtained by R. Vaglio (Napoli) et al. in situ using magnetron sputtering on MgO and other substrates held at about 800^oC. The best films showed maximum Tc = 15.1 K with Delta-Tc ~~ 0.1 K. From experiments using a variety of techniques, including low-temperature STM, the authors concluded that YNi2B2C is a moderately anisotropic metal, exhibiting conventional s-wave BCS superconductivity.

HTS on Ni Tapes

Techniques for sputter deposition of biaxially oriented buffer layers on thermomechanically textured Ni tapes are reported by Q. He et al. (Oak Ridge). One approach is to deposit epitaxial Pd or Pt films as a base layer and then to deposit biaxially oriented Ag or CeO2 buffer layers. Using Ar/4%H2 sputter gas, biaxially oriented CeO2 films also were grown directly on the textured Ni tapes, followed by epitaxial growth of YSZ films. The authors report that thick YBa2Cu3O7-d films were grown on the YSZ/CeO2 buffer layers, and that these YBCO deposits had biaxial alignment and self-field Jc = 7 x 10^5 A/cm^2 at 77 K, with a magnetic- field dependence Jc(B) similar to that of YBCO epitaxial thin films grown on oxide single crystals such as SrTiO3.

Two preprints by R. L. Meng et al. (TCSUH) report the fabrication of HgBa2Ca2Cu3O8+d (Hg-1223) tapes on flexible Ni substrates coated with Cr/(Ag,Pd) using a technique in which c-axis-oriented micrograins of HgBa2CaCu2O6+d (Hg-1212) serve as the nucleation sites for large c-axis- oriented Hg-1223 grain growth. The self-field Jc of these Hg-1223 tapes is reproducibly 7 x 10^4 A/cm^2 at 77 K.

Vortices

Coherent terahertz spectroscopy has been used by R. Mallozzi (UC- Berkeley and LBNL) et al. to measure the complex resistivity of thin films of Bi2Sr2CaCu2O8+d (Bi-2212) in the vortex state as a function of frequency (50-250 GHz), temperature, and magnetic field. At high frequencies, the observed field dependence is inconsistent with conventional models based on vortex motion. To explain their results, the authors present a model based on the nonlinear London electrodynamics predicted for a d-wave superconductor. According to this model, the high-frequency electrodynamic response in the vortex state is dominated by enhanced pair breaking due to nodes in the gap function. Quantitative agreement with experiment is found using only parameters obtained from zero-field measurements of the complex conductivity and angle-resolved photoemission.

New data obtained by A. Schilling (Lawrence Berkeley National Laboratory) et al. using high-resolution differential thermal analysis (DTA) reveals that the vortex lattice of untwinned YBa2Cu3O7-d in the mixed state (for magnetic fields parallel to the crystalline c axis) undergoes a first-order phase transition. The phase-transition line H_m(T) in the magnetic phase diagram coincides with the vortex-lattice melting line that previously had been deduced from resistivity and magnetization measurements. The value obtained for the latent heat, L~~ 0.5 k_BT per vortex per superconducting layer, is consistent with that inferred from magnetization data using the Clapeyron equation, thus proving thermodynamic consistency of the data. The specific heat C of the vortex fluid is found to be larger than that of the vortex solid. The specific-heat difference Delta-C and the measured latent heat L are independent of the measuring speed and the path used to cross H_m(T) in the H-T phase diagram.

A preprint by A. Junod et al. (Geneve) reports results of adiabatic specific-heat experiments on YBa2Cu3O7.00 performed in magnetic fields (B||c and Bperp. to c) from 0 to 16 T. The sample was a twinned, 99.995% pure 18 mg crystal grown in an inert BaZrO3 crucible and oxidized in high oxygen pressure to suppress the magnetic fishtail effect. First-order-like specific-heat peaks rising up to 1.1% above the background were observed at the melting line of the vortex lattice from 6 to 16 T (B||c). The entropy under these peaks is (0.6+-0.1)k_B per vortex per superconducting layer. Thermodynamically incompatible specific-heat steps and magnetization jumps were observed below 6 T (B||c), suggesting irreversible glassy behavior.

The properties of the Bose-glass phase of localized flux lines in irradiated superconductors near the matching field B_[phi] have been studied theoretically by C. Wengel (UC-Santa Cruz) and U. C. Taeuber (Oxford and Linacre College). The authors find that repulsive vortex interactions destroy the Mott insulator phase that was predicted to occur at B = B_[phi]. For ratios of the penetration depth to average defect distance lambda/d <= 1, remnants of the Mott insulator singularities remain visible in the magnetization, bulk modulus, and magnetization relaxation as B is varied near B_[phi]. For lambda/d >= 1, the ensuing weakly pinned Bose glass is characterized by a soft Coulomb gap in the distribution of pinning energies.

YBa2Cu3O7-d

The ac Hall effect of YBa2Cu3O7-d in the normal state has been measured by B. Parks (UC-Berkeley and LBNL) et al. using time-domain spectroscopy. In contrast to some theories that explain the anomalous Hall effect by postulating a much slower quasiparticle scattering rate for Hall conduction than for normal conduction, the authors report a Hall scattering rate that is consistent with the normal scattering rate.

Using transmission electron microscopy (TEM), G. Du et al. (TCSUH) have systematically studied weakly coupled (low-Jc) and strongly coupled (high-Jc) grain boundaries with 35-degree and 54-degree misorientation angles, respectively, in melt-textured YBCO. The authors find that the misorientation angle is not the decisive factor in determining the grain-boundary coupling, but that the strength of the coupling is determined mainly by the extent of oxygenation in the boundary.

The physical properties and microstructure of melt-textured YBa2Cu3O7- d/Y2BaCuO5 (123/211) have been investigated by I. Monot (Caen) et al. For samples doped with 2 wt% CeO2 and 0.5% PtO2, the 77 K critical current density was magnetically determined to be 5.6 x 10^4 A/cm^2 in self-field and 4.3 x 10^4 A/cm^2 in a field of 1 T.

The magnetoresistance of YBa2Cu3O7-d crystals (Tc = 90 K) and Zn-doped YBCO crystals has been measured by K. Semba and A. Matsuda (NTT). The authors conclude that the Maki-Thompson fluctuation contribution is vanishingly small.

Bi Cuprates

The losses in Bi-2223 tapes subjected to ac magnetic fields have been measured by M. P. Oomen (Siemens) et al. for various orientations of B with respect to the tape. The authors find that when the ac loss in parallel and perpendicular fields is known, the loss at intermediate angles can be predicted over a wide range of field amplitudes. For low field amplitudes, the current patterns that would be induced in the tape by the parallel and perpendicular field components alone can be summed, while for high field amplitudes, the tape carries only the current pattern induced by the perpendicular component.

A thermometric method for measuring the self-field losses of Ag-sheathed (Bi,Pb)-2223 tapes carrying ac current is described by T. Hughes et al. (Southampton). The loss is determined by measuring the temperature profile along the length of a vacuum-insulated tape whose ends are maintained at a fixed base temperature. Measurements of the losses at 47 Hz and 507 Hz show a contribution (~10%) at the higher frequency due to eddy currents induced in the silver sheath by the perpendicular component of the self-field.

A study of the 77 K critical currents I_c of different Ag-sheathed Bi- 2223 tapes has been carried out by J. Horvat et al. (Wollongong). Plots of I_c vs. H were used to separate the critical currents due to weak (I_c^w) and strong (I_c^s) links. The zero-field ratio I_[c0]^s/I_[c0] was found to be correlated with the critical current density J_[c0]; this ratio can be used as a reliable parameter for determining the quality of the links between grains.

Other Cuprates

The local structure of the electron-doped infinite-layered superconductor (Sr1-yCay)1-xLaxCuO2 (0 <= x <= 0.12, 0 <= y <= 0.20) as determined by its extended x-ray absorption fine structure (EXAFS) has been studied by G. Er et al. (Osaka). The author found that both Sr1- xLaxCuO2 (0 <= x <= 0.12) and (Sr1-yCay)0.9La0.1CuO2 (0 <= y <= 0.20) have local structure consistent with that expected from the ideal infinite-layer structure at room temperature, without obvious deviation of oxygen ions from the CuO2 plane.

The structure of HgBa2CuO4+d (Hg-1201) in the pressure range 0-5.07 GPa has been investigated at room temperature by V. L. Aksenov (JINR-Dubna) et al. using neutron powder diffraction. The authors determined the compressibility values of the unit cell parameters and several bond distances.

Thin Films

The microwave properties of 0.4 micrometer-thick films of YBa2Cu3O7-d on polycrystalline substrates with ion-beam-assisted-deposited (IBAD) yttria-stabilized zirconia (YSZ) buffer layers have been studied by A. T. Findikoglu et al. (Los Alamos) using a parallel-plate resonator technique at 10 GHz. Low-power surface resistance R_s values of about 0.5 milliohms at 76 K and 0.15 milliohm at 4 K were obtained for films with an in-plane mosaic spread of about 7 degrees. At high power levels, the data suggest that hysteretic vortex penetration into weak links is the most plausible source of the observed nonlinearities.

As reported by E. L. Venturini (Sandia) et al., lattice damage introduced into high-temperature superconducting Tl2Ba2CaCu2O8+d (Tl- 2212) thin films by irradiation with 60 MeV Cu^[+9] ions produces a large enhancement in both the critical current density J_[cm] and the vortex volume pinning force. These effects were observed for a fluence (2 x 10^[11] ions/cm^2) that causes only a small decrease (~4%) in Tc.

The superconducting gap symmetry in YBa2Cu3O7-d has been investigated by Y. Ishimaru et al. (SRL-ISTEC) using Josephson junctions at the (a/c) boundary of an a-axis grain surrounded by c-axis-oriented grains. There are two types of a/c boundary junctions with (001) a-axis grains: one with (100) of c-axis grains and the other with (110) of c-axis grains. The authors find that in (001)-(100) a/c junctions, I_c has a conventional magnetic-field dependence of I_c with a maximum at zero magnetic field (0-junction behavior); however, in (001)-(110) a/c junctions, I_c has a minimum at zero magnetic field (pi-junction behavior).

The properties of a long, current-biased 0-pi-0 Josephson junction (positive critical current for |x| > a and negative critical current for |x| < a) have been theoretically studied by T. Kato and M. Imada (Tokyo). The authors find that if the pi-junction length 2a is much larger than the Josephson penetration length lambda_J, a half vortex (carrying flux phi_0/2, where phi_0 = h/2e) is found at one end of the pi-junction, and an antivortex (flux -phi_0/2) at the other end.

Applications

A paper by V. Meerovich (Ben-Gurion University of the Negev) et al. deals with anomalous phenomena recently observed in operation of models of inductive high-Tc superconducting YBCO current limiters. The anomalies appear as sharp peaks of voltage or current on the background of a basic ac signal. The authors demonstrate that these anomalies are due to self-oscillations appearing in an electric circuit with nonlinear superconducting elements. These self-oscillations can result in the destruction of insulation, disturbances of the normal operation of control devices, and the undesirable generation of high-frequency harmonics in a network.

Theory

An explanation of why d-wave pairing is robust in the presence of defects and impurities is offered in a preprint by M. L. Kulic (MPI- Stuttgart) and V. Oudovenko (MPI-Stuttgart and JINR-Dubna). The authors attribute this to the appearance of a forward peak in the charge scattering channel at low doping levels. For large doping, however, the scattering anisotropy parameter is small, and d-wave pairing loses its robustness.

An expression for the dynamic spin susceptibility in the two-dimensional Hubbard model has been derived by I. Eremin (Kazan and Zurich). The formula can be used to calculate the spin susceptibility for real hole- doped high-Tc superconductors.

According to a preprint by V. P. Gusynin et al. (Kiev), the temperature vs. carrier-density phase diagram of a 2D metal consists of three regions: (a) a normal phase, where the absolute value of the order parameter is zero, (b) an abnormal phase, where the absolute value of the order parameter is nonzero but its phase is random, and (c) the Berezinskii-Kosterlitz-Thouless phase.

A paper by H. Haugerud (Oslo) et al. starts from the Emery model for CuO chain fragments and uses an extended ASYNNNI (asymmetric next-nearest- neighbor Ising) model to study the statistical mechanics of O atoms in oxygen-deficient CuOx chain layers in RBa2Cu3O6+x (R = rare earth or Y). The authors use Monte Carlo techniques to compute the charge transfer to the CuO2 planes (which regulates high-Tc superconductivity) and the concentration of differently coordinated Cu ions.

The properties of an S/Fi/S Josephson junction, which has a ferromagnetic layer as the insulator, have been studied theoretically by Y. Tanaka (Niigata) and S. Kashiwaya (ETL-Tsukuba). The Josephson current formula, which is expressed in terms of the energy levels of bound states located near the interface, shows an anomalous dependence on the magnitude of the exchange interaction at the insulator. As the interaction strength is increased, the Josephson junction changes from a 0-junction to a pi-junction.

Numerical and analytical studies of ac + dc driven Josephson-junction arrays with a single vortex or with a single vortex-antivortex pair present have been carried out by P.H.E. Tiesinga (Utrecht) et al. Single-vortex steps in the voltage vs. current (V-I) characteristics are found, which correspond to a single vortex phase-locked to move a fixed number of plaquettes per period of the ac driving current. In underdamped arrays, the authors find vortex-motion period doubling on the steps.

The second-order Doppler shift of the Mossbauer spectra in a superconductor has been calculated by L. S. Lingam and K. N. Shrivastava (Hyderabad). The shift depends on the fourth power of the ratio of the superconducting energy gap to the matrix element of the electron-phonon interaction.

Other Activities

Though this report undoubtedly will prove to be highly controversial, E. E. Podklenov (Moscow Chemical Scientific Research Center) describes further experiments claiming weak gravitational shielding properties of a composite bulk YBa2Cu3O7-d superconductor. The author prepared a toroidal disk using conventional ceramic technology in combination with melt-textured growth. Two solenoids were placed around the disk to initiate current inside it and to provide rotation about its central axis. The author reports that samples of metals, plastic, ceramic, wood, etc., placed over the rotating (5000 rpm) disk demonstrated a weight loss of 0.3-0.5%. When the rotation speed was slowly reduced by changing the current in the solenoids, the shielding effect reportedly became considerably higher and reached 1.9-2.1% at a rotation speed of 3500 rpm.

A preprint by G. Modanese (INFN-Povo) and J. Schnurer (Physics Engineering) proposes a theory of quantum gravity effects in a charged Bose condensate under a variable electromagnetic field. The authors also describe preliminary experiments indicating gravitational shielding by a YBa2Cu3O7-d superconducting disk.

Magnetization measurements on a weakly ferromagnetic Pd/0.5 at% Fe alloy (Curie temperature Tc = 15 K) are reported by H. Claus (Argonne and Illinois-Chicago) and B. W. Veal (Argonne). In fields above 200 mG, the magnetization is typical of a ferromagnet, but when cooling in small fields (H < 25 mG), the magnetization reverses its direction at low temperatures, apparently becoming diamagnetic. The effect is very similar, but of opposite sign, to that observed in some high-Tc superconducting samples where the magnetization becomes paramagnetic on field cooling (paramagnetic Meissner effect, PME). For the ferromagnetic sample, the effect is simply explained in terms of dipolar polarization of the bulk of the sample by a surface layer with enhanced Tc. Removing this surface layer eliminates the anomalous effect, and the sample behaves like an ordinary ferromagnet down to the lowest fields.

Overviews

Rapid single flux quantum (RSFQ) logic, a digital circuit technology based on superconducting Josephson junctions, has a significant potential for large-scale, ultra-high-speed, low-power digital applications. K. Gaj et al. (Rochester) have prepared a comprehensive review of RSFQ timing from the viewpoint of the principles, concepts, and language developed for semiconductor VLSI. The authors note that the RSFQ technology may be the first to cross the boundary of 100 GHz clock frequency in a large-scale digital circuit (80 refs.).

Ph.D. Theses

Experimentally determined properties of the flux-line solid and liquid in amorphous Nb3Ge films are reported in the Ph.D. thesis of M. H. Theunissen (Leiden). The author used a device consisting of weak- pinning channels surrounded by strong-pinning regions. The critical current at the onset of flux flow in such a device is a probe of the shear modulus of the vortex solid. The device also permits the determination of the shear viscosity in the vortex-liquid state (121 refs.).

Critical fluctuations and vortex dynamics in Josephson-junction arrays were examined via numerical simulations in P. Tiesinga's (Utrecht) Ph.D. thesis. The author studied vortex fluctuations in thermal equilibrium, the dynamics of Josephson-junction arrays with a finite penetration depth, single-vortex-induced Shapiro steps in arrays, arrays with different forms of dissipation, and chaos-induced coherent states (116 refs.).

The Ph.D. thesis of P. A. Zoller (Tuebingen) reports experimental studies of high-temperature superconductivity and resistive behavior in bismuth cuprates related to Bi2Sr2CaCu2O8+d (Bi-2212). Textured samples with nominal stoichiometries Bi0.4Pb0.35Sr2Y0.8Ca0.2Cu2.05O7-z, Bi0.4Pb0.4Sr2Y0.7Ca0.3Cu2.05O7-z, and Bi0.4Pb0.45Sr1.9Y0.7Ca0.4Cu2.15O7- z were prepared and studied. The author also used a dc SQUID to magnetically determine the intragranular critical current density Jc (76 refs.).

Contributed by John R. Clem

Contents: Technology News begins on page 5; Preprints begin on page 6; Coming Events begin on page 12; and Resources are 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.

TECHNOLOGY NEWS (Also see Applications section of Nota Bene.)

This section describes progress in manufacturing, product development, and technology transfer in the high-Tc superconductivity field. Please send your contributions (product development information, news regarding technology transfer efforts, or any information you would like to share about your corporation or laboratory) to the editor.

New Network: SCENET -- The European Network for Superconductivity. Objectives of SCENET is to: i) bring together fundamental and applied academic groups as well as industrial ones; ii) transfer knowledge from academic institutions to industry; iii) promote pre-competitive research among industrial groups; and iv) establish a technological road map for future research needs in superconductivity for industrial applications. The Network links government laboratories, universities, and industrial laboratories of the European Community, Switzerland, and Norway to formulate short- and medium-term technological goals, and aims to single out those applications which will allow the European industry to compete in the world markets and identify groups that have the expertise to develop new competitive products for a global market. The Network will be directed by a 15-member Steering/Organizing Committee of which 4 members will be industrial members representing power applications, device applications, materials processing, enabling science (including both applied and basic sciences), and education, with additional members chosen to ensure an appropriate European dimension. The Network will initially include 60 nodes from government research organizations, academia, and industry. Subsequently, membership will be open to any appropriate group by application. For information, contact Andrea Gauzzi, MASPEC-CNR, Via Chiavari 18/A, I-43100 Parma, Italy; telephone +39 521 269 200; telefax +39 521 292 932; e-mail gauzzi@maspec.bo.cnr.it.

Successful installation of the first commercially operational high- temperature superconducting device for electrical utility service was announced by Asea Brown Boveri (ABB). The fault current limiter, designed to protect power system equipment and personnel from the effects of short-circuit electrical faults, will undergo long-term performance monitoring under actual operating conditions. The current limiter, developed in ABB's Corporate Research Laboratories, was installed in the Kraftwerk am Loentsch hydroelectric power plant, near Glarus in central Switzerland, and has a rating of 1 MVA at a system voltage of 10.5 kilovolts. Financial support for the commercial development and testing of the device was provided by the Swiss Utilities Study Fund (PSEL) with practical assistance provided by NOK. For further information, contact Willi Paul, ABB Corporate Research, Baden-Daettwil, CH-5405, Switzerland; telephone +41 56 486-8146; telefax +41 56 486-7314; e-mail willi.paul@chcrc.abb.ch.

Contributed by Sreeparna Mitra

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.

A. G. Abanov and P. B. Wiegmann, "Tunneling and Orthogonality Catastrophe in the Topological Mechanism of Superconductivity." James Franck Institute, University of Chicago, 5640 S. Ellis Avenue, Chicago, IL 60637; e-mail agabanov@midway.uchicago.edu; preprint also available at cond-mat@xxx.lanl.gov (#9701163).

V. L. Aksenov, A. M. Balagurov, B. N. Savenko, D. V. Sheptyakov, V. P. Glazkov, V. A. Somenkov, S. Sh. Shilshtein, E. V. Antipov, and S. N. Putilin, "Investigation of the HgBa2CuO4+d Structure under External Pressures up to 5 GPa by Neutron Powder Diffraction." To be published in Physica C (in press). Contact A. M. Balagurov, Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, 101000 Moscow Region, RUSSIA; telefax +7 096 21 65882; e-mail bala@nf.jinr.ru. Key words: high pressure effect, neutron diffraction, structure of HgBa2CuO4+d .

J. A. Alonso, C. Cascales, P. Garcia Casado, and I. Rasines, "On Characterization of Barium Rare-Earth Antimonates, Ordered Perovskites Suitable as Substrates for Superconducting Films." Submitted to J. Solid State Chem. Contact I. Rasines, Instituto de Ciencia de Materiales, CSIC, Cantoblanco, E-28049 Madrid, SPAIN; telephone +34 1 334 9068; telefax +34 1 372 0623; e-mail immir@csic.pinar1.es.

E. B. Amitin, V. Ya. Dikovsky, and M. Yu. Kameneva, "Peculiarities of Kinetic Phenomena in YBCO: Phase Separation or 'Devil's Staircase'?" Submitted to Low Temp. Phys. Contact V. Ya. Dikovsky, Institute of Inorganic Chem., 3, Acad. Lavrent'ev Ave., Novosibirsk 630090, RUSSIA; e-mail dikovsky@casper.che.nsk.su. Preprint in Russian.

Y. Cao, F. Y. Lin, Z. L. Du, F. Chen, Y. Y. Xue, and C. W. Chu, "Annealing and Thermoelectric Power of (Cu,C)-1223, (Cu,C)-1234 and Ba2Ca2Cu3(CauCuv)O8+d." Preprint #97:009; submitted to Physica C: the Proc. of the 5th Int. Conf. on Mater. and Mech. of Supercond. -- High- Temp. Supercond. (M^2S-HTSC V), Beijing, People's Republic of China, Feb. 28-Mar. 4, 1997. 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.

X. H. Chen, T. F. Li, R. P. Wang, Y. M. Qiu, K. Q. Ruan, L. Z. Cao, L. Shi, Y. B. Jia, G. E. Zhou, and Y. H. Zhang, "Anomalies Induced by Calcium Doping in NdCeCuO System." Department of Physics, University of Science & Technology of China, Academia Sinica, Heifei, Anhui 230026, PEOPLE'S REPUBLIC OF CHINA.

L. Civale and L. Krusin-Elbaum, "Comment on 'Upper Limit of the Bose- Glass Transition in YBa2Cu3O7 at High Density of Columnar Defects.'" To be published in Phys. Rev. Lett. IBM Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, NY 10598.

H. Claus and B. W. Veal, "Apparent Diamagnetic Response of an Inhomogeneous Ferromagnet." Submitted to Phys. Rev. B. Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov.

John R. Clem, Thomas Pe, and Maamar Benkraouda, "The Role of 2D Pancake Vortices in High-Temperature Superconductors." Submitted to Physica C: Proc. of the 5th Int. Conf. on Mater. and Mech. of Supercond. -- High- Temp. Supercond. (M^2S-HTSC V), Beijing, People's Republic of China, Feb. 28-Mar. 4, 1997. Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, IA 50011-3160; telephone (515) 294-4223; telefax (515) 294-0689; e-mail clem@ameslab.gov.

M. Daeumling and W. Goldacker, "Specimen Geometry Effects on the Irreversible Magnetization in the Low Field Regime for Specimens of Bulk Nb3Sn." To be published in Z. Phys. B. Forschungszentrum Karlsruhe, Institut fuer Technische Physik, Postfach 3640, D-76021 Karlsruhe, GERMANY. 74.25.Ha; 74.60.Jg; 74.70.Ad.

Y. De Wilde, M. Iavarone, U. Welp, V. Metlushko, A. E. Koshelev, I. Aranson, and G. W. Crabtree, "STM Observation of a Square Abrikosov Lattice in LuNi2B2C." Submitted to Phys. Rev. Lett. Contact Janice Coble, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telefax (708) 252-9595; e-mail janice_coble@qmgate.anl.gov.

C. Diaz-Guerra and J. Piqueras, "Cathodoluminescence Microscopy and Spectroscopy of Superconducting Bi2Sr2CaCu2O8+x Single Crystals." To be published in Physica C (in press). Departamento de Fisica de Materiales, Facultad de Ciencias, Fisicas, Universidad Complutense, Ciudad Universitaria s/n, E-28040 Madrid, SPAIN; telefax +34 1 394 4547. 74.72.Hs; 78.60.Hk.

V. Ya. Dikovsky, A. N. Lavrov, L. P. Kozeeva, E. V. Matizen, and A. P. Shelkovnikov, "Applicability of the Resonant Tunnelling Idea to Anisotropic Conductivity of TmBCO Crystals." To be published in JETP Lett. Institute of Inorganic Chem., 3, Acad. Lavrent'ev Ave., Novosibirsk 630090, RUSSIA; e-mail dikovsky@casper.che.nsk.su. Preprint in Russian.

G. Du, M. K. Mironova, S. Sathyamurthy, and K. Salama, "Possible Strong Coupling for High-Angle Grain Boundaries in YBCO Superconductor." Preprint #97:007; 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.

G. Er, S. Kikkawa, M. Takahashi, and F. Kanamaru, "Studies on Local Structure of Infinite-Layered (Sr1-yCay)1-xLaxCuO2 (0<=x<=0.12, 0<=y<=0.20) Superconductor." To be published in Physica C (in press). Department of Chemistry and Materials Technology, Kyoto Institute of Technology, Matsugasaki, Sakyoku, Kyoto 606, JAPAN. Key words: local structure, infinite layer, superconductor, EXAFS, oxygen ions, CuO2 plane.

I. Eremin, "Dynamic Susceptibility in Two-Dimensional Hubbard Model." To be published in Physica B. Theoretical Physics, Kazan State University, Lenin str. 18, Kazan 420008, RUSSIA; telefax: +7 8432 380994; e-mail ilya.eremin@ksu.ru. Key words: high-Tc superconductors, spin fluctuations, two-dimensional system.

M. Eremin, S. Varlamov, I. Eremin, D. Brinkmann, R. Markendorf, M. Mali, and J. Roos, "The Model of Singlet-Correlated Bands for Temperature and Doping Dependences of Cu(2) Knight Shift in Bilayered Cuprates." To be published in Physica B (in press). Department of Physics, Kazan State University, Lenin str. 18, Kazan 420008, RUSSIA; e-mail mikhail.eremin@ksu.ru. Key words: singlet-correlated band, spin susceptibility, bilayered cuprates.

Y. Feng, K. Q. Ruan, K. Q. Wang, C. Y. Wang, L. Z. Cao, Q. L. Xu, F. Foong, B. Bedard, and S. H. Liou, "Evidence of the Spin Gap in Hg0.9Tl0.1Ba2Ca2Cu3O8+d." Department of Physics, University of Science & Technology of China, Academia Sinica, Heifei, Anhui 230026, PEOPLE'S REPUBLIC OF CHINA.

Alp T. Findikoglu, David W. Reagor, Paul N. Arendt, Steven R. Foltyn, James R. Groves, Quanxi X. Jia, Eric J. Peterson, Lev Boulaevskii, and Martin P. Maley, "Microwave Properties of Superconducting Yttrium- Barium-Copper Films on Buffered Polycrystalline Substrates." Preprint No. LA-UR-97-9752; submitted to Appl. Phys. Lett. Superconductivity Technology Center, Los Alamos National Laboratory, Mail Stop K763, Los Alamos, NM 87545; telephone (505) 667-3569; telefax (505) 665-8601; e- mail findik@lanl.gov. 74.76.Bz; 74.80.Dm; 85.25.Jw; 81.15.-z.

F. Forsthofer, Ch. Helm, Ch. Preis, J. Keller, K. Schlenga, R. Kleiner, and P. Mueller, "Coupling Between Phonons and Intrinsic Josephson Oscillations in Cuprate Superconductors." To be presented at the 1997 Int. Symp. on Intrinsic Josephson Effect and THz Plasma Oscillations in High Tc Supercond., Sendai, Japan, Feb. 23-25, 1997; submitted to Phys. Rev. Lett. Institut fuer Theoretische Physik, Universitaet Regensburg, D-93040 Regensburg, GERMANY; Ch. Helm's telephone +49 941 943 2046; telefax +49 941 943 4382; e-mail christian.helm@physik.uni- regensburg.de; preprint also available at cond-mat@xxx.lanl.gov (#9701049).

Kris Gaj, Eby G. Friedman, and Marc J. Feldman, "Timing of Multi- Gigahertz Rapid Single Flux Quantum Digital Circuits." To be published in J. of VLSI Signal Processing. Department of Electrical Engineering, University of Rochester, Rochester, NY 14627.

R. S. Gonnelli, G. A. Ummarino, and V. A. Stepanov, "Determination of the Tunneling Electron-Phonon Spectral Function in High-Tc Superconductors with Energy Dependence of the Normal Density of States." To be published in Physica C (in press). INFM-Dipartimento di Fisica, Politecnico di Torino, I-10129 Torino, ITALY; telephone +39 11 5647350; telefax +39 11 5647399; e-mail gonnelli@polito.it; preprint also available at cond-mat@xxx.lanl.gov (#9612220). Key words: Eliashberg equations, electron-phonon coupling, phonon mechanism. 74.50.+r.

V. P. Gusynin, V. M. Loktev, and S. G. Sharapov, "Phase Diagram of 2D Metal System with Arbitrary Carrier Density." Submitted to JETP Lett. Bogolyubov Institute for Theoretical Physics, Metrologicheskaya Str. 14b, 252143 Kiev, UKRAINE; V. M. Loktev's e-mail vloktev@gluk.apc.org. 74.20.-z; 74.25.-q; 74.72.-h; 67.20.+k; 67.40.-w.

Harek Haugerud, Gennadi Uimin, and Walter Selke, "From Microscopic Description to Statistical Mechanics of Cu-O Chain Fragments in the High-Tc Superconductors REBa2Cu3O6+x." Department of Physics, University of Oslo, P.O. Box 1048, Blindern, 0316 Oslo, NORWAY; e-mail harek.haugerud@fys.uio.no; preprint also available at cond- mat@xxx.lanl.gov (#9612072). Key words: REBCO compounds, Cu-O chains, Emery model, ASYNNNI model.

Qing He, D. K. Christen, J. D. Budai, E. D. Specht, D. F. Lee, A. Goyal, D. P. Norton, M. Paranthaman, F. A. List, and D. M. Kroeger, "Deposition of Biaxially-Oriented Metal and Oxide Buffer-Layer Films on Textured Ni Tapes: New Substrates for High-Current, High-Temperature Superconductors." To be published in Physica C (in press). Contact D. K. Christen, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6061; telefax (423) 574-6263; e-mail dkc@ornl.gov. Key words: applications of high-Tc superconductors, grain alignment (texturing), multilayers, thin films. 81.15.Cd; 85.25.Kx; 68.55.Jk.

J. Horvat, W. G. Wang, R. Bhasale, Y. C. Guo, H. K. Liu, and S. X. Dou, "Critical Currents in Ag/Bi-2223 Superconducting Tapes: Grain Connectivity and Flux Pinning." Submitted to Physica C. Centre for Superconducting and Electronic Materials, University of Wollongong, NSW 2522, AUSTRALIA; telephone +61 42 21 5722; telefax +61 42 21 5731; e- mail jhorvat@uow.edu.au.

T. Hughes, A. E. Mahdi, Y. Yang, and C. Beduz, "Comparative Thermometric and Electric Measurements of the Self-Field ac Losses in Ag-Sheathed PbBi2223 Tapes." To be published in Physica C (in press). Institute of Cryogenics, Southampton University, Southampton SO17 1BJ, UNITED KINGDOM.

Yoshihiro Ishimura, Jianguo Wen, Naoki Koshizuka, and Youichi Enomoto, "Superconducting Gap Symmetry Study Using a/c Boundary Josephson Junctions in Y1Ba2Cu3O7-d Films." 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.

Valery Ivanov, Kyuya Yakushi, and Elana Ugolkova, "Electronic Structure of kappa-ET2X Salts, Where 'ET' is Bis(Ethylenedithio) Tetrathiafulvalene (BEDT-TTF) Molecule." To be published in Physica C (in press). Institute for Molecular Science, Nishigonaka 38, Myodaiji- cho, Okazaki 444, JAPAN. Key words: band structure, Hubbard Hamiltonian, energy gap, organic conductors.

Alain Junod, Marlyse Roulin, Jean-Yves Genoud, Bernard Revaz, Andreas Erb, and Eric Walker, "Specific Heat Peaks Observed up to 16 Teslas on the Melting Line of the Vortex Lattice in YBa2Cu3O7." To be published in Physica C. Departement de Physique de la Matiere Condensee, Universite de Geneve, CH-1211 Geneve 4, SWITZERLAND. 74.25.Bt; 74.60.Ge; 74.72.Bk.

M. Kambara, M. Nakamura, Y. Shiohara, and T. Umeda, "Quasi-Binary Phase Diagram of Nd4Ba2O10-Ba3Cu5O8 System." To be published in Physica C (in press). Department of Metallurgy, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, JAPAN. Key words: Nd123, phase diagram, liquidus line, peritectic temperature.

M. Karppinen, H. Yamauchi, H. Suematsu, K. Isawa, M. Nagano, R. Itti, and O. Fukunaga, "Control on the Copper Valence and Properties by Oxygen Content Adjustment in the LaCuO3-y System (0<=y<=0.5). Submitted to J. Solid State Chem. Contact H. Yamauchi, Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226, JAPAN; telephone +81 45 924 5315; telefax +81 45 921-6935 or -5360; e-mail yamauchi@materia.titech.ac.jp.

Takeo Kato and Masatoshi Imada, "Vortices and Quantum Tunneling in Current-Biased 0-pi-0 Josephson Junctions of d-Wave Superconductors." Submitted to J. Phys. Soc. Jpn. Institute for Solid State Physics, University of Tokyo, 7-22-1 Roppongi, Minato-ku, Tokyo 106, JAPAN; telephone +81 3 478 6811; telefax +81 3 401 5169; e-mail tkato@eagle.issp.u-tokyo.ac.jp; preprint also available at cond- mat@xxx.lanl.gov (#9701147). Key words: high-Tc superconductor, pi junction, sine-Gordon equation, half vortex, macroscopic quantum tunneling.

K. Kobayashi and J. Yoshida, "Thermogravimetric Analyses of Hydrogen Doped La2-xSrxCuO4 and Effects of Hydrogen Atoms on Superconductivity." To be published in Physica C (in press). Department of Applied Chemistry, Faculty of Engineering, Ehime University, 3, Bunkyo-ku, Matsuyama 790, JAPAN.

S. Kondo, D. C. Johnston, C. A. Swenson, F. Borsa, A. V. Mahajan, L. L. Miller, T. Gu, A. I. Goldman, M. B. Maple, D. A. Gajewski, E. J. Freeman, N. R. Dilley, R. P. Dickey, J. Merrin, K. Kojima, G. M. Luke, Y. J. Uemura, O. Chmaissem, and J. D. Jorgensen, "LiV2O4: A Heavy Fermion Transition Metal Oxide." Submitted to Phys. Rev. Lett. Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, IA 50011; D. C. Johnston's telephone (515) 294-5435; telefax (515) 294-0689; e-mail johnston@ameslab.gov. 75.20.Hr; 75.40.Cx; 76.60.-k.

Miodrag L. Kulic and Viktor Oudovenko, "Why is d-Wave Pairing in HTS Robust in the Presence of Impurities?" Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, GERMANY; Viktor Oudovenko's e-mail udo@audrey.mpi-stuttgart.mpg.de; preprint also available at cond-mat@xxx.lanl.gov (#9612211).

G. A. Levin, T. Stein, C. N. Jiang, C. C. Almasan, D. A. Gajewski, S. H. Han, and M. B. Maple, "In-Plane and Out-of-Plane Resistivities of PrBa2Cu3O7-d and Y0.47Pr0.53Ba2Cu3O7-d Single Crystals." Submitted to Physica C: Proc. of the 5th Int. Conf. on Mater. and Mech. of Supercond. -- High-Temp. Supercond. (M^2S-HTSC V), Beijing, People's Republic of China, Feb. 28-Mar. 4, 1997. Contact Carmen C. Almasan, Department of Physics, Kent State University, Kent, OH 44242; telephone (330) 672-2402; telefax (330) 672-2959; e-mail calmasan@physics.kent.edu.

Lydia S. Lingam and Keshav N. Shrivastava, "Dendritic Phase Boundary of a Superconductor." To be published in Mod. Phys. Lett. School of Physics, University of Hyderabad, P. O. Central University, Hyderabad 500 046, INDIA; Keshav N. Shrivastava's telephone +91 40 3010 227; telefax +91 40 3010 120; e-mail kns.sp@uohyd.ernet.in.

Lydia S. Lingam and Keshav N. Shrivastava, "Mossbauer Second-Order Doppler Shift and the Recoilless Fraction of [119]^Sn in Superconductors." To be published in Mod. Phys. Lett. School of Physics, University of Hyderabad, P. O. Central University, Hyderabad 500 046, INDIA; Keshav N. Shrivastava's telephone +91 40 3010 227; telefax +91 40 3010 120; e-mail kns.sp@uohyd.ernet.in.

J. Garcia Lopez, J. Siejka, L. M. Mercandalli, R. Bisaro, M. G. Blanchin, and V. Teodorescu, "Formation of YBa2Cu3O7 Tetragonal Phase by Rapid Cooling of Thin Films Grown by Cathodic Sputtering." To be published in Physica C (in press). Groupe de Physique des Solides des Universites Paris 7 et 6, URA 17 du CNRS, Tour 23, 2 Place Jussieu, F- 75251 Paris Cedex 05, FRANCE. Key words: YBaCuO, tetragonal structure, in-situ growth.

M. Lorenz, H. Hochmuth, D. Natusch, H. Boerner, T. Thaerigen, D. G. Patrikarakos, J. Frey, K. Kreher, S. Senz, G. Kaestner, D. Hesse, M. Steins, and W. Schmitz, "Large-Area and Double-Sided Pulsed Laser Deposition of Y-Ba-Cu-O Thin Films Applied to HTSC Microwave Devices." Presented at the Appl. Supercond. Conf., Pittsburgh, PA, Aug. 25-30, 1996; to be published in IEEE Trans. Appl. Supercond. Universitaet Leipzig, Institut fuer Experimentalphysik II, D-04103 Leipzig, GERMANY.

R. Mallozzi, J. Orenstein, J. N. Eckstein, and I. Bozovic, "High- Frequency Electrodynamics of Bi2Sr2CaCu2O8+d: Nonlinear Response in the Vortex State." Materials Science Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, CA 94720.

N. S. Manton, "First Order Vortex Dynamics." Preprint #DAMTP 96-111. Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Silver Street, Cambridge CB3 9EW, ENGLAND; e-mail n.s.manton@damtp.cam.ac.uk; preprint also available at hep- th@xxx.lanl.gov (#9701027).

V. Meerovich, V. Sokolovsky, G. E. Shter, G. S. Grader, A. B. Kozyrev, V. N. Osadchy, and E. K. Holmann, "Self-Oscillations in Circuits with High-Tc Superconducting Current Limiters." To be published in Physica C (in press). Department of Physics, Ben-Gurion University of the Negev, P.O. Box 653, 84105 Beer-Sheva, ISRAEL.

R. L. Meng, K. Lewis, Y. Q. Wang, C. Garcia, L. Gao, Y. Y. Xue, and C. W. Chu, "Two-Step Spray/Press Process for Hg-1223 Tape Fabrication." Preprint #97:006; submitted to Physica C. 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: high-temperature superconductivity, Hg-based high-temperature superconductors, critical current density, two-step processing. 74.72.Jt; 74.72.Lw; 85.25.Kx.

R. L. Meng, Y. Q. Wang, K. Lewis, C. Garcia, L. Gao. Y. Y. Xue, and C. W. Chu, "Fabrication and Microstructure of Hg-1223 Tape." Preprint #97:008; submitted to Physica C: the Proc. of the 5th Int. Conf. on Mater. and Mech. of Supercond. -- High-Temp. Supercond. (M^2S-HTSC V), Beijing, People's Republic of China, Feb. 28-Mar. 4, 1997. 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.

Giovanni Modanese and John Schnurer, "Possible Quantum Gravity Effects in a Charged Bose Condensate under Variable e.m. Field." I.N.F.N., Gruppo Collegato di Trento, Dipartimento di Fisica dell'Universita, I- 38050 Povo, ITALY; e-mail modanese@science.unitn.it. 04.20.-q; 04.60.- m; 74.72.-h.

I. Monot, K. Verbist, M. Hervieu, P. Laffez, M. P. Delamare, J. Wang, G. Desgardin, and G. Van Tendeloo, "Microstructure and Flux Pinning Properties of Melt Textured Grown Doped YBa2Cu3O7-d." To be published in Physica C (in press). Laboratoire CRISMAT, CNRS, URA 1318, ISMRA/Universite de Caen, Boulevard du Marechal Juin, F-14050 Caen Cedex, FRANCE.

V. N. Narozhnyi, "Superconductor-Insulator Transition in Gd1- xPrxBa2Cu3O7-y Single Crystals: Investigation in High Magnetic Fields." Presented at the Int. Conf. on Electron Localization and Quantum Transport in Solids (Localization'96), Jaszowiec, Poland, Aug. 3-6, 1996. Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk, Moscow Region, 142092, RUSSIA; telephone +7 095 334 08 08; telefax +7 095 334 00 12; e-mail narozh@ns.hppi.troitsk.ru.

V. N. Narozhnyi, V. N. Kochetkov, A. V. Tsvyashchenko, and L. N. Fomicheva, "Hall-Effect Study of YNi2B2C Superconductor." Presented at the Int. Conf. on Phys. and Chem. of Molecular and Oxide Supercond. (MOS'96), Karlsruhe, Germany, Aug. 2-6, 1996; to be published in J. Low Temp. Phys. Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk, Moscow Region, 142092, RUSSIA; telephone +7 095 334 08 08; telefax +7 095 334 00 12; e-mail narozh@ns.hppi.troitsk.ru. 74.70.Ad; 72.15.Gd; 74.60.Ec.

M. P. Oomen, J. Rieger, and M. Leghissa, "Field-Angle Dependence of ac Loss in Multi-Filamentary High-Tc Superconducting Tapes." Submitted to Appl. Phys. Lett. Siemens AG, ZT EN 4, P.O. Box 3220, D-91050 Erlangen, GERMANY; telephone +49 91317-34889; telefax +49 91317-33323; e-mail martino.leghissa@erls.siemens.de.

Beth Parks, S. Spielman, J. Orenstein, and Paul Merchant, "High Frequency Hall Effect in the Normal State of YBa2Cu3O7." Materials Science Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, CA 94720. 74.25.Ha; 74.25.Gz; 78.20.Ls.

E. E. Podkletnov, "Weak Gravitation Shielding Properties of Composite Bulk YBa2Cu3O7-x Superconductor Below 70 K under e.m. Field." Moscow Chemical Scientific Research Centre, 113452 Moscow, RUSSIA; e-mail modanese@science.unitn.it; preprint also available at cond- mat@xxx.lanl.gov (#9701074). 74.72.-h.

H. D. Ramsbottom and D. P. Hampshire, "Improved Critical Current Denisty and Irreversibility Line in HIP'ed Chevrel Phase Superconductor PbMo6S8." To be published in Physica C (in press). Contact D. P. Hampshire, Department of Physics, University of Durham, Science Laboratories, South Road, Durham DH1 3LE, UNITED KINGDOM; telefax +44 191 374 3749; e-mail d.p.hampshire@durham.ac.uk. Key words: chevrel superconductors, critical current, hot isostatic press.

K. Q. Ruan, Y. Feng, C. Y. Wang, X. H. Chen, and L. Z. Cao, "Evidence of the Spin Gap in Bi2Sr2Ca1-xYxCu2Oy Single Crystals." Department of Physics, University of Science & Technology of China, Academia Sinica, Heifei, Anhui 230026, PEOPLE'S REPUBLIC OF CHINA.

K. Q. Ruan, Y. Feng, C. Y. Wang, X. H. Chen, L. Z. Cao, Q. L. Xu, F. Foong, B. Bedard, and S. H. Liou, "Hall Effect Studies of the Mixed State of c-Axis Oriented Hg0.9Tl0.1Ba2Ca2Cu3O8+d Superconducting Films with Tc > 124K." Department of Physics, University of Science & Technology of China, Academia Sinica, Heifei, Anhui 230026, PEOPLE'S REPUBLIC OF CHINA.

A. Schilling, R. A. Fisher, N. E. Phillips, U. Welp, W. K. Kwok, and G. W. Crabtree, "Calorimetric Evidence for the Occurrence of a First-Order Transition in the Mixed State of Untwinned YBa2Cu3O7." To be presented at the 5th Int. Conf. on Mater. and Mech. of Supercond. -- High-Temp. Supercond. (M^2S-HTSC V), Beijing, People's Republic of China, Feb. 28- Mar. 4, 1997. Department of Chemistry, University of California, Berkeley, CA 94720-1460.

Kouichi Semba and Azusa Matsuda, "Vanishingly Small Maki-Thompson Superconducting Fluctuation in the Magnetoresistance of High-Tc Superconductors." To be published in Phys. Rev. B. Materials Science Laboratory, NTT Basic Research Laboratories, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-01, JAPAN; telephone +81 462 40 3342; telefax +81 462 70 2362; e-mail semba@will.brl.ntt.co.jp or semba@with.brl.ntt.co.jp.

E. Silva, S. Sarti, M. Giura, R. Fastampa, and R. Marcon, "Anisotropy and Dimensionality of Bi2Sr2CaCu2O8+x from Transport Measurements." To be published in Phys. Rev. B. Dipartimento de Fisica "E. Amaldi" and INFM, Universita di Roma Tre, Via della Vasca Navale, 84, I-00146 Roma, ITALY; telefax +39 6 557 9303; e-mail silva@roma1.infn.it. 74.25.Fy; 74.72.Hs; 74.80.-g.

U. Staub, R. Osborn, E. Balcar, L. Soderholm, and V. Trounov, "The Wave Vector Dependence of Intermultiplet Transitions in EuBa2Cu3Ox (x=6.1 and 7): An Inelastic Neutron Scattering Study." To be published in Phys. Rev. B. Swiss Light Source Project, Paul Scherrer Institute, CH-5232 Villigen PSI, SWITZERLAND; telephone +41 56 310 4494; telefax +41 56 310 3151; e-mail urs.staub@psi.ch. 71.70.Ch; 74.72.Jt; 71.70.Ej; 25.40.Fq.

M. Stebelski, M. Szopa, and E. Zipper, "Coherence of Currents in Mesoscopic Cylinders." To be published in Z. Phys. B. Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, POLAND; telephone +48 32 583653; telefax +48 32 588431; e-mail mstebels@us.edu.pl; preprint also available at cond-mat@xxx.lanl.gov (#9701183). Key words: mesoscopic cylinder, Fermi surface, spontaneous currents. 71.30.+h; 72.10.-d.

A. M. Suvarna and C. S. Sunandana, "ESR of DPPH Decorated CuO: A Phase Transition Study." To be published in Physica C (in press). Contact C. S. Sunandana, School of Physics, University of Hyderabad, Hyderabad 500 046, INDIA; telefax +91 40 258 120; e-mail css.sp@uohyd.ernet.in.

Yukio Tanaka and Satoshi Kashiwaya, "Theory of Josephson Effect in Superconductor--Ferromagnetic-Insulator--Superconductor Junction." To be published in Physica C (in press). Department of Physics, Graduate School of Science and Technology, Niigata University, Ikarashi, Niigata 950-21, JAPAN.

M. H. Theunissen, "Properties of the Flux-Line Solid and Liquid in Amorphous Nb3Ge Films." Submitted as a Ph.D. thesis (Leiden University). Kamerlingh Onnes Laboratorium, Leiden University, 2300 RA Leiden, THE NETHERLANDS.

P.H.E. Tiesinga, T. J. Hagenaars, J. E. van Himbergen, and Jorge V. Jose, "Single-Vortex-Induced Voltage Steps in Josephson-Junction Arrays." Instituut voor Theoretische Fysica, Princetonplein 5, Postbus 80006, 3508 TA Utrecht, THE NETHERLANDS; Jorge V. Jose's e-mail jose@citlalli7.physics.neu.edu; preprint also available at cond- mat@xxx.lanl.gov (#9612230). 74.50.+r; 74.60.Ge; 74.60.Jg.

Paul Hendrik Edward Tiesinga, "Critical Fluctuations and Vortex Dynamics in Josephson-Junction Arrays." Submitted as a Ph.D. thesis (Universiteit Utrecht). Instituut voor Theoretische Fysica, Princetonplein 5, Postbus 80006, 3508 TA Utrecht, THE NETHERLANDS.

C. V. Tomy, G. Balakrishnan, and D. McK. Paul, "Regions of Enchanced Pinning in the Mixed State of the Superconductor Yb3Rh4Sn13." Submitted to Physica C. Contact G. Balakrishnan, Department of Physics, University of Warwick, Coventry CV4 7AL, UNITED KINGDOM; telephone +44 1203 523 -523, ext 2238 or -356; telefax +44 1203 692 016; e-mail phryj@csv.warwick.ac.uk. Key words: superconductivity, peak effect, Stannides, pinning.

Toshiyuki Usagawa, Yoshihiro Ishimaru, Jianguo Wen, Satoshi Koyama, and Youichi Enomoto, "(110) YBa2Cu3O7-d Homoepitaxy on (110) YBa2Cu3O7-d Single Crystal Substrates." Superconductivity Research Laboratory, International Superconductivity Technology Center (ISTEC), 10-13 Shinonome 1-chome, Koto-ku, Tokyo 135, JAPAN; telephone +81 3 3536-5703 through -5705; telefax +81 3 3536-5714 or -5717. Key words: (110) YBa2Cu3O7-d single crystals, homoepitaxy, AFM, TEM, RHEED, off-axis rf magnetron sputtering, surface flatness.

R. Vaglio, A. Andreone, C. Aruta, A. Cassinese, F. Fontana, G. W. Crabtree, M. Iavarone, Y. De Wilde, L. Maritato, C. Attanasio, C. Coccorese, M. Salluzzo, and M. Salvato, "Properties of YNi2B2C Superconducting Thin Films." Submitted to Phys. Rev. B. Istituto Nazionale per la Fisica della Materia (INFM), Dipartimento di Scienze Fisiche, Universita di Napoli Federico II, Piazzale Tecchio 80, I-80125 Napoli, ITALY.

E. L. Venturini, P. P. Newcomer, H. Schoene, B. L. Doyle, and K. E. Myers, "Strongly Enhanced Vortex Pinning in High-Energy, Heavy-Ion- Irradiated, Superconducting Tl-Ba-Ca-Cu-O Films." Presented at the Tenth Int. Conf. on Ion Beam Modification of Materials, Albuquerque, NM, Sept. 1-5, 1996; to be published in Nucl. Instr. Methods in Phys. Res. B. Sandia National Laboratories, MS 1421, Albuquerque, NM 87185-1421; telephone (505) 844-7055; telefax (505) 844-4045; e-mail elventu@sandia.gov.

Yanhui Wang, Bruce A. Scott, Bai-Hao Chen, and David Walker, "The Role of Contamination in Sr-Cu-O Reactions at High Pressure." To be published in Physica C (in press). Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964; telefax (914) 365-8155; e-mail yywang@ldeo.columbia.edu.

J. C. Wei, J. L. Chen, R. S. Liu, and T. J. Yang, "Interaction Between a Cylindrical Superconducting Impurity and a Vortex in a Type-II Superconductor." To be published in Physica C (in press). Contact T. J. Yang, Department of Electro-Physics, National Chiao-Tung University, Hsinchu, Taiwan, REPUBLIC OF CHINA; telefax +886 35 725 230.

Carsten Wengel and Uwe Claus Taeuber, "Weakly Pinned Bose Glass vs. Mott Insulator Phase in Superconductors." Submitted to Phys. Rev. Lett., Department of Physics, University of California, Santa Cruz, CA 95064; e-mail wengel@chopin.ucsc.edu; preprint also available at cond- mat@xxx.lanl.gov (#9612093). 74.60.Ge; 05.60.+w.

J. Wosik, L. M. Xie, K. Nesteruk, D. Li, J. H. Miller, Jr., and S. A. Long, "Power Handling Capabilities of Superconducting YBCO Thin Films: Thermally Induced Nonlinearity Effects." Preprint #97:005; submitted to the Proc. of the Fourth Symp. on High Frequency Characterization of HTS, Asilomar, CA, Sept. 29-Oct. 2, 1996. Texas Center for Superconductivity, University of Houston, Houston, TX 77204; telephone (713) 743-8237; telefax (713) 743-8201; e-mail jarek@uh.edu. Key words: surface impedance, microwave power handling capability, defects in superconducting films, heat transfer, rf breakdown fields, dielectric cavity.

Y. Y. Xue, Y. Y. Sun, Z. L. Du, I. A. Rusakova, D. K. Ross, N. L. Wu, Y. Cao, L. Gao, and C. W. Chu, "The Structures of the 126 K Ba2Ca2Cu3(CaxCuy)O8+d, the 116 K Ba2Ca3Cu4(CaxCuy)O10+d and Their Transformed Products." Preprint #97:010; submitted to Physica C: the Proc. of the 5th Int. Conf. on Mater. and Mech. of Supercond. -- High- Temp. Supercond. (M^2S-HTSC V), Beijing, People's Republic of China, Feb. 28-Mar. 4, 1997. 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.

Peter Alexander Zoller, "High-Temperature Superconductivity and Resistive Behavior in Bismuth-Cuprates of 1212 Type." Submitted as a Ph.D. thesis (Universitaet Tuebingen). Institut fuer Anorganische Chemie, Universitaet Tuebingen, Auf der Morgenstelle 18, D-72076 Tuebingen, GERMANY.

Changfei Zhu, Jinrui Su, Shixing Wang, Wei Liu, Xisheng Luo, and Liezhao Cao, "Ultrasonic Behavior in La2-xBaxCuO4-y Polycrystalline Superconductor." Department of Physics, University of Science & Technology of China, Academia Sinica, Heifei, Anhui 230026, PEOPLE'S REPUBLIC OF CHINA. Key words: La2-xBaxCuO4-y, ceramic, ultrasonic velocity, ultrasonic attenuation.

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

April 10 - 12, 1997: Materials for Power Applications: Workshop of the European Network for Superconductivity, Kassel, Germany. Topics are: HTS materials processing; activities in Europe; global progress on materials processing; HTS wires and tapes; and strategies (short and long term, and selected areas to focus on based on industrial needs). For information, contact Andrea Gauzzi, Via Chiavari 18/A, I-43100 Parma, Italy; telephone +39 521 269 200; telefax +39 521 292 932; e-mail gauzzi@maspec.bo.cnr.it.

June 8 - 12, 1997: Fifth International Seminar on Highly Conducting Organic Materials for Molecular Electronics (ISME'97), Poznan- Puszczykowo, Poland. Topics include theory of conducing crystals, polymers, and films; syntheses of new organic conducting materials; structure and properties of organic conductors; fullerenes, fullerides, nanotubes, and graphic materials; low-dimensional molecular systems; and multi-component and heterogeneous organic devices. Abstract deadline, May 15, 1997. For information, contact A. Graja, Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznan, Poland; telephone +48 61 612 -475 or -365; telefax +48 61 684 524; e- mail graja@ifmpan.poznan.pl.

*June 8 - 20, 1997: NATO Advanced Study Institute on Applications of Superconductivity, Hotel Alexandra, Loen, Norway. The scientific bases, technological issues, and market potential of all current and emerging applications will be considered. These will include fabrication of cables and magnets; power conditioning and transmission; energy storage; microwave electronics; SQUID magnetometry in biomagnetism, geophysics, and nondestructive evaluation; and analog and digital circuitry. Cryogenic and materials issues will be covered. Application deadline, February 24, 1997.** For information on financial assistance and/or application, contact Harold Weinstock, AFOSR/NE, Bolling AFB, DC 20332- 8080; telefax (202) 767-4986; e-mail harold.weinstock@afosr.af.mil. (The preferred mode of communication is e-mail.) **Note new application deadline.

*July 14 - 16, 1997: Symposium on Synthesis, Properties and Applications of High Temperature Superconductors, Gold Coast, Queensland, Australia. Topics include (but are not limited to): powder synthesis and novel processing; chemistry, phase relationships, and nonstoichiometry; relationships between microstructures and properties; flux pinning and weak links; anisotropy and two-dimensional behavior; transport and magnetic properties; mechanical properties; processing for the development of flux pinning centers; fabrication of wires, tapes, magnets, and bulk materials; and applications and future trends. Contact T. Chandra, Department of Materials Engineering, University of Wollongong, Wollongong 2522, Australia; telefax +61 42-213 112 or -214 921; e-mail t.chandra@uow.edu.au.

*July 19 - 27, 1997: Third International Summer School on High Temperature Superconductivity, Eger, Hungary. Objective is to provide overview of basic and up-to-date information on the theories and newest results in fundamental research and applications of high-temperature superconductors. Last days of the School to be devoted to a scientific conference (poster sessions and 15-minute oral presentations) for participants to present results of their own scientific work. Topics include: second decade of high-Tc superconductivity, new theories, physical properties, characterization and measurements of physical properties, new trends in preparation techniques, crystal structures, physical properties and morphology, manufacturing, and small and large- scale applications. Abstract deadline, March 1, 1997. Proceedings to be published; tutorial lectures to be published as a textbook, "Textbook of the Summer School." Official language is English. For further information contact Istvan Vajda, Department of Electrical Machines and Drives, Technical University of Budapest, Egry Jozsef utca 18, H-1111 Budapest, Hungary; telephone +36 1 463-2961 or -3600; e-mail vajda@ntb.bme.hu; Web site http://docs4.mht.bme.hu/~farkas.

*Sept. 1 - 12, 1997: NATO Advanced Study Institute on the Gap Symmetry and Fluctuations in High-Tc Superconductors, Institut d'Etudes Scientifiques de Cargese, Corse, France. Objective is to give advanced lectures on the most recent progress in understanding of the physics of high-temperature superconductors with a special emphasis on the symmetry of the superconducting gap and critical fluctuations. Pedagogical explanation of various theoretical models and a direct comparison with recent (often controversial) experiments is the central point of this Advanced Study Institute. A dedicated www site with more details will be announced in January 1997. For preliminary information contact Davor Pavuna, telephone +41 21-6933301; telefax +41 21-6934666; e-mail pavuna@eldp.epfl.ch.

*Sept. 7 - 20, 1997: Summer School on Superconductivity in Networks and Mesoscopic Structures, Certosa di Pontignano, Siena, Italy. Aimed at Ph.D. students and postdoctoral researchers. School will provide opportunity for interaction with experts from different fields and include topics such as simulation of complex dynamic systems, quantum and classical theories, Monte Carlo simulations, and others. Six days of lessons, with afternoons available for working groups and additional seminars. Proceedings to be published by World Scientific. Limited number of grants are available and can be requested via the Web or e- mail. Grant application deadline, April 15, 1997. Contact C. Giovannella, Dipartimento di Fisica, Universita di Roma "Tor Vergata", Via della Ricerca Scientifica 1, I-00133 Rome, Italy; telephone +39 6 7259 4524; telefax +39 6 202 3507; e-mail supnet@roma2.infn.it. Information also available at the web site http://wwwas.roma2.infn.it/.

*Sept. 14 - 18, 1997: Conference on Spectroscopies in Novel Superconductors (SNS '97), Sea Crest Oceanfront Resort and Conference Center, Falmouth, Cape Cod, MA. Conference sponsored by the College of Arts and Sciences as part of centennial celebration of the founding of Northeastern University. For further information, contact Prof. Arun Bansil, Conference Chair, Department of Physics, Northeastern University, Boston, MA 02115, telephone (617) 373-2923; or Julie Pumphrey, Conference Secretary, The Barnett Institute, Northeastern University, Boston, MA 02115, telephone (617) 373-2868, telefax (617) 373-2855.

Jan. 6 - 9, 1998: 7th Joint MMM-Intermag Conference, San Francisco, CA. Conference will include all basic and applied science technology related to magnetism. The technical subject categories are: cooperative phenomena and fundamental magnetic properties, transport properties, computational magnetics and imaging, soft magnetic materials and applications, hard magnetic materials and applications, other materials, artificially structured materials, magnetic recording, and interdisciplinary topics and applications. Invited talks, oral presentations, and poster sessions. Exhibition of services, equipment, and materials. Abstract deadline, July 9, 1997. Proceedings to be published in special issues of J. Appl. Phys. and IEEE Trans. on Mag. For further information, contact Diane Suiters or Amy Landsbaum, Conference Coordinators, 655-15th Street N.W., Suite 300, Washington, DC 20005; telephone (202) 639-5088; telefax (202) 347-6109; e-mail magnetism@courtesy.assoc.com. Technical questions regarding abstracts should be directed to one of the Program Chairs: Alison Chaiken, Mailstop L-350, Lawrence Livermore Laboratory, Livermore, CA 94550; telephone (510) 422-7129, telefax (510) 422-6892, e-mail chaiken@llnl.gov; or Toasz Jagielinski, Eastman Kodak Company, 3985 Sorrento Valley Boulevard, San Diego, CA 92121, telephone (619) 535- 6908, telefax (619) 535-6990, e-mail tmj@kodaksdl.com.

RESOURCES

Information

New Directory: Commonwealth of Independent States --1996-1997 Directory of Physics and Astronomy Staff, by S.I. Shkuratov and E.F. Talantsev. Comprises of five parts and contains information about 5,151 professional scientists from more than 540 Institutions of the Republics of former USSR: Armenia, Azerbaijan, Belarus, Estonia, Georgia, Kazakhstan, Kyrgyzstan, Latvia, Lithuania, Moldova, Russia, Tajikistan, Turkmenistan, Ukraine, and Uzbekistan. Directory consists of alphabetical lists of physics and astronomy staff, research and academic institutions, staff members of the National Academies of Sciences, and research organizations and academic institutions. To be publ. fall 1997; 516 pp.; price $69.45; ISBN 5-7691-0553-4. For information, contact S.I. Shkuratov, Institute of Electrophysics, Urals Division of the Russian Academy of Sciences, 34 Komsomolskaya Str., Ekaterinburg, 620049, Russia; telephone +7 3432 49-91-80; telefax +7 3432 44-50-51; e- mail shkurato@ief.intec.ru.

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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. 11, #4, February 15, 1997.