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, 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:

Correction: The preprint of I. Isaac and J. Jung (Alberta) listed in our Feb. 1 issue studied a divergence of the logarithmic decay rate S(T,H) close to Tc in granular YBCO samples, and not in single crystals and epitaxial thin films, where the same phenomenon is observed.

Theory

According to a preprint by Z.-X. Shen (Stanford) and J. R. Schrieffer (Florida State), the anomalous momentum and temperature dependence of the spectral lineshape observed in underdoped Bi2Sr2CaCu2O8+d (Bi-2212) indicates that the quasiparticles are strongly coupled to collective excitations centered near q = (pi,pi). The doping dependence of the spectral lineshape and its correlation with the size of the superconducting gap indicate that these collective excitations are related to the pairing interaction in high-Tc superconductors, in analogy with phonon-induced structures in tunneling spectra of low-Tc materials.

Quantum Monte Carlo (QMC) and maximum entropy (ME) techniques have been used by D. Duffy (Florida State) et al. to study the spectral function A(p,omega) of the one-band Hubbard model in strong coupling, including a next-nearest-neighbor electronic hopping with amplitude t'/t = -0.35. The parameters are chosen to improve the comparison of the Hubbard model with angle-resolved photoemission (ARPES) data for high-Tc cuprates in the antiferromagnetic insulator regime.

A self-consistent theory, called the irreducible Green's function (IGF) method, which enables the calculation of quasiparticle spectra in highly correlated systems, is presented in a preprint by A. L. Kuzemsky (JINR- Dubna). The author discusses in detail the application of the IGF method to the Hubbard model and the random Hubbard model. The author also briefly discusses other applications to the s-f model, Anderson model, Heisenberg antiferromagnet, electron-phonon interaction models, and quasiparticle tunneling.

The role of a finite potential range of a nonmagnetic impurity for the local density of states in a d_[x^2-y^2] superconductor has been considered by A. P. Kampf (Koeln) and T. P. Devereaux (George Washington). The authors find that impurity-induced subgap resonances are modified by the appearance of further scattering channels beyond the s-wave scattering limit. The structure of the local density of states (DOS) in the vicinity of the impurity is significantly enhanced and thus improves the possibility for observing the characteristic anisotropic spatial modulation of the local DOS in a d_[x^2-y^2] superconductor by scanning tunneling microscopy (STM).

A preprint by E. Sherman (Moscow Institute of Physics and Technology) uses a model including interaction of carriers with B_[1g] and A_[1g] phonons and electronic correlations in the CuO2 planes to show that the B_[1g] phonon charge fluctuations lead to a considerable modulation of the t-J model parameters.

The effect of interband transitions on the c-axis conductivity, dc resistivity, and thermal conductivity in a plane-chain bilayer model of a cuprate has been considered by W. C. Wu (McMaster) et al. The authors identify the pseudogap as the minimum energy for interband transitions possible in a given band structure.

A preprint by R. A. Klemm (Argonne) gives various reasons to doubt experiments that have provided evidence for d-wave symmetry of the superconducting order parameter in the high-temperature superconductors. The author also proposes that the pseudogap recently observed in underdoped cuprates could arise from a charge-density wave.

The effect of density-of-states fluctuations on the thermoelectric coefficient beta in a superconductor above its critical temperature has been studied by D. V. Livanov (Moscow Institute for Steel and Alloys) et al. The authors show that in the isotropic case it is the DOS contribution that gives rise to the leading correction to beta, in contrast to previous results where only the Aslamazov-Larkin term was taken into account. This conclusion is valid for arbitrary impurity concentration.

Polarization-dependent ARPES experiments have revealed the presence of two different Zhang-Rice singlets in the two-dimensional Cu3O4 planes of insulating Ba2Cu3O4Cl2. Using model calculations, M. S. Golden (Dresden) et al. find that one of these singlets is moving in the antiferromagnetically ordered cuprate-like Cu_AO2 subsystem, and the other is moving on the effectively paramagnetic sublattice formed by the extra Cu_B atoms. The dispersion of the former is determined by the superexchange integral J_A, while that of the latter is determined by the hopping integral t_B.

A preprint by I. Aranson (Bar Ilan and Argonne) et al. reports analytical and numerical studies of population dynamics on a rugged landscape within a model for the evolution of N individuals in one- dimensional fitness space. The authors obtain results that are analogous to the thermally activated creep of a particle in a random pinning potential.

Vortices

The angular dependence of the vortex velocity correlation temperature T_[th](H) in twinned YBa2Cu3O7-d single crystals has been measured by E. Morre et al. (Bariloche). The data show that the c-axis-correlated vortex-liquid phase exists up to angles much larger than expected within a single-vortex pinning picture. Despite this, the second-order solid- liquid glass transition is shown to be restricted to external magnetic fields applied within a few degrees of the c-axis direction.

Measurements of the magnetoresistivity rho(B,T) as a function of temperature T in magnetic fields B up to 0.7 T have been carried out by A. V. Pop (Cluj-Napoca) et al. on a sample of (Bi1.6Pb0.4)(Sr1.8Ba0.2)Ca2Cu3O10+d (Bi-2223, Tc = 110 K). The d[rho]/dT vs. T curves in an applied magnetic field reveal the intra- and intergranular transitions as a function of B. The authors studied thermally activated flux motion and found that the activation energy is proportional to (1-T/Tc)lnB, which suggests a 2D state in which the dissipation is dominated by flux-line cutting in an entangled vortex liquid.

The classical and quantum creep rates of vortices pinned by columnar defects have been calculated by C. Morais Smith (Hamburg) et al. within the framework of continuum elastic theory. They develop a general model that accounts simultaneously for the massive, dissipative, and Hall dynamics. The authors determine the crossover temperature separating the thermal and quantum regimes by using perturbation theory around the thermal solution. The calculations are performed for anisotropic vortex lines and 2D pancake vortices. The authors compare their results with experiments in BSCCO and YBCO.

Magnetoresistance measurements of the effects of 1 GeV [238]^U^[40+] ion irradiation in a clean, untwinned single crystal of YBa2Cu3O7-d have been carried out by L. M. Paulius (Argonne and Western Michigan) et al. The authors find that the onset of pinning from the columnar defects occurs very close to the zero-field superconducting transition temperature, well into the vortex-liquid state. The authors also find that the dissipative behavior of vortex flow due to the Lorentz force is similar to the dissipation of two resistors in series.

Two preprints by A. K. Pradhan (SRL-ISTEC and Indore) et al. report on the effects of pinning by columnar defects on magnetotransport and magnetization properties of Bi2Sr2CaCu2O8+d single crystals irradiated by 250 MeV [107]^Ag^[14+] ions. The authors find that the magnetoconductivity is dominated by the dynamics of 2D pancake vortices near Tc but that the vortices have a line-like behavior at low temperatures.

The effects of static disorder on the vortex dynamics of type-II superconductors have been investigated by N.-C. Yeh (Caltech) et al. by comparing the high-frequency vortex response of superconducting amorphous Mo3Si (a-Mo3Si) films with that of high-temperature superconductors. The authors find that for a-Mo3Si films in the three- dimensional limit, the microwave vortex response near the second-order vortex-solid to vortex-liquid glass transition is consistent with vortex critical relaxation, in contrast to the diffusion vortex dynamics in high-temperature superconductors at the same frequencies.

A preprint by W. Jiang (Caltech) et al. reports investigations of current-driven vortex dynamics in an untwinned YBa2Cu3O7-d single crystal in the weak-pinning limit. Resistive peaks in the current- dependent vortex dissipation are quantitatively analyzed in terms of the current-driven coherent and plastic motion of vortex bundles in the vortex-solid phase, and the nonlinear current-voltage characteristics are found to be consistent with the collective flux-creep model.

The free energy of a system of two vortex lines pointing in different directions, with their average direction making an angle theta with respect to the crystal c axis, has been calculated by E. Sardella (Bauru) as a function of the angle 2[alpha] between them. The author finds for sufficiently high anisotropy that there is a range of theta values between 0 degree and 90 degrees for which inclined vortex lines (alpha not equal to 0) have a lower energy than parallel vortex lines (alpha = 0).

Magneto-optical observations by V. K. Vlasko-Vlasov (Argonne and ISSP- Chernogolovka) et al. have revealed the presence of cylindrical Meissner holes, regions of zero magnetic field between oppositely magnetized regions of YBa2Cu3O7-d crystals. Large supercurrents flow near the surfaces of the Meissner-hole cylinders.

Superconductors containing paramagnetic ions that interact with the superconducting electrons via electromagnetic fields are considered theoretically by D. P. Hampshire (Durham). The author postulates that when these materials are superconducting, a consequence of the phase coherence of the superelectrons is that if the external magnetic field is changed after equilibrium is reached, no heat is produced or absorbed by the paramagnetic ions. He finds that in high magnetic fields, when the magnetic susceptibility chi of the paramagnetic ions obeys 0 <= chi << 1, the superconductor behaves like a standard type-II material, and when chi >> 1, the material behaves ferromagnetically and there is a square flux-line lattice. The author describes the magnetic phases present for different values of chi and provides experimental evidence for them in ErRh4B4.

RBa2Cu3O7-d

Melt-textured bars of YBa2Cu3O7-d (10 cm length and 5 mm diameter) have been found by L. Porcar et al. (Grenoble) to be able to carry pulsed transport currents up to 6,000 A at 77 K. Such high currents were possible because of the high quality of the contacts to YBCO.

A preprint by W.-J. Jang et al. (SRL-ISTEC) reports electron-density maps of tetragonal YBa2Cu3O6 and orthorhombic YBa2Cu3O6.9 obtained by x- ray diffraction. The authors point out the differences in the local electron density distributions in these two materials.

Studies of phase formation in the Nd1+xBa2-xCu3O6.5+x/2+d system have been carried out by P. Yossefov (Technion) et al. The highest Tc (98.7 K) was found for the x = 0 case.

Bi Cuprates

As reported by M. R. Norman (Argonne) et al., photoemission spectra of Bi2Sr2CaCu2O8+d (Bi-2212) below Tc show two features near the (pi,0) point of the zone: a sharp peak at low energy and a higher binding energy hump. The authors find that the sharp peak persists at low energy even as one moves toward (0,0), while the broad hump shows significant dispersion correlating well with the normal-state dispersion. They argue that these features are naturally explained by the mixing of electrons with a bosonic mode that appears only below Tc, and they speculate that the latter may be related to the resonance seen in recent neutron data.

A preprint by S. Tirumala (TCSUH) et al. reports the effects of thermomechanical processing and reaction kinetics of Bi-2223 powder-in- tube superconducting tapes made from aerosol precursor powder, which has been shown to have the advantage of reduced processing time.

Other Cuprates

The infrared reflection spectra of a La2CuO4.06 single crystal have been measured by R.P.S.M. Lobo (Orleans and Paris) et al. on the ab plane in the normal and superconducting states. The authors find a nonconventional thermal evolution of the reflectivity over the entire measured range (20 - 10000 cm^[-1]). Using a Kramers-Kronig analysis of the data, the authors separate the contributions from the normal state and Cooper-pair condensation. The measurements are explained in terms of a charge delocalization into a large polaron, with transfer of spectral weight from high frequencies to a Drude-like peak.

Quasiparticle tunneling measurements of the high-temperature superconductors HgBa2Can-1CunO2n+2+d (n = 1, 2, and 3) have been carried out by J.Y.T. Wei (Columbia) et al. and analyzed in the context of a d_[x^2-y^2] symmetry of the superconducting order parameter and a two- dimensional (2D) Van Hove singularity (VHs) related to saddle points in the electronic band structure. NIS tunneling spectra taken at 4.2 K with a scanning tunneling microscope (STM) on Hg-1212 c-axis epitaxial films, as well as on Hg-1201 and Hg-1223 polycrystalline samples, show distinct gap characteristics, which cannot be easily reconciled with a simple s-wave BCS density of states.

Films

The electric-field effect on the transport properties of ultrathin Y0.9Pr0.1Ba2Cu3O7-d channels has been examined by U. Kabasawa (Hitachi) et al. as a function of channel thickness and channel length. Samples having a planar YBa2Cu3O7-d/Y0.9Pr0.1Ba2Cu3O7-d/YBa2Cu3O7-d structure with a gate electrode on the back side of the SrTiO3 substrate were used. The channel layer exhibited superconducting properties when its thickness was more than 9 nm, but channels of thickness less than 7.5 nm were insulating. The modulation ratio of the conductance of insulating (I-phase) channels was a few orders of magnitude higher than the modulation ratio of the carrier density. The field-effect mobility increased with increasing channel thickness when the film was in the insulating phase. The sheet conductance of channels shorter than 10 micrometers was higher than that of a 100 micrometers channel of the same thickness. The authors conclude that the performance of possible field-effect transistors with high-temperature superconductors may be much improved by utilizing short I-phase channels.

The superconducting transitions in a Tl2Ba2CaCu2O8+d (Tl-2212) thin film and a Tl-2212 polycrystal have been studied by J. C. Soret (Tours) et al. The authors find two kinds of voltage-current behaviors. They find universal scaling properties of a Kosterlitz-Thouless-like phase transition for the film and a three-dimensional phase-coherence transition for the polycrystal.

The microstructure of YBa2Cu3O7-d (YBCO) grain boundaries at step edges on (001) LaAlO3 substrates has been studied by M. Gustafsson et al. (Chalmers) using scanning and transmission electron microscopy. The detailed grain-boundary morphology is determined by the film growth and nucleation characteristics.

Other Activities

From measurements of the far-infrared reflectivity at grazing angles of incidence with p-polarized light, J. Schuetzmann (Groningen) et al. have determined the c-axis Josephson plasma frequencies of the single-layer high-Tc cuprates Tl2Ba2CuO6+d (Tl-2201) and La2-xSrxCuO4. The authors detected a strong plasma resonance at 50 cm^[-1] for La2-xSrxCuO4, which is in excellent agreement with previously published results. For Tl- 2201, the authors were able to determine that the unscreened c-axis Josephson plasma frequency omega_J is less than 100 cm^[-1], which corresponds to the c-axis penetration depth being greater than 15 micrometers. The small value of omega_J stands in contrast to a recent prediction based on the interlayer tunneling mechanism of superconductivity.

A peak in the electronic Raman scattering spectra of Y-123, Y-124, Bi- 2212, Tl-2201, and La-124 single crystals has been observed by O. V. Misochko (ISSP-Chernogolovka) and E. Ya. Sherman (Moscow Institute of Physics and Technology) and identified as the Van Hove singularity. The authors assert that the singularity results in charge redistribution within one band for electronic scattering and between two bands for phonon scattering.

A preprint by H. A. Blackstead (Notre Dame) and J. D. Dow (Arizona State and Tsinghua, Beijing) presents arguments that all high-temperature oxide superconductors are necessarily p-type, including Nd2-xCexCuO4, which is generally regarded as being n-type. Tests are suggested.

The unoccupied electronic structure of the one-dimensional cuprate-based compound SrCuO2 has been studied by M. Knupfer (Dresden) et al. using x- ray absorption spectroscopy. By choosing the orientation of the single crystals with respect to the polarization vector of the synchrotron radiation, the authors were able to determine the hole occupation of the different O 2p and Cu 3d orbitals. The authors show that the intrinsic holes in the one-dimensional copper-oxide zigzag chains mainly occupy planar 3d_[x^2-y^2] orbitals, which closely resembles the situation in the undoped parent compounds of the high-temperature superconductors.

Overview

Optical spectroscopic studies of the high-Tc superconducting cuprates have been reviewed by S. Tajima (SRL-ISTEC). Topics discussed include doping-induced changes in the electronic structure, anisotropy and the out-of-plane charge dynamics, and the electron-phonon interaction. The author also discusses the in-plane and out-of-plane optical response in the superconducting state, including evidence for a Josephson plasma (113 refs.).

Contributed by John R. Clem

Contents: Preprints begin on page 4; Coming Events begin on page 11; Resources are on page 13; and FYI is 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.

M. V. Abrashev, A. P. Litvinchuk, C. Thomsen, and V. N. Popov, "Optical Phonons in the Orthorhombic Double-Chain Sr1-xCaxCuO2 (x=0,0.5)." To be published in Phys. Rev. B. Institut fuer Festkoerperphysik, Technische Universitaet Berlin, Hardenbergstrasse 36, D-10623 Berlin, GERMANY; telephone +49 30 314-22083; telefax +49 30 314-27705; e-mail abrashev@lise.physik.tu-berlin.de. 78.30.Hv; 63.20.Dj; 74.72.Jt.

V. L. Aksenov, "Neutron Investigations of Surfaces and Thin Films." Preprint #P14-96-350. Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, RUSSIA; telefax +7 095 975 23 81.

C. C. Almasan, G. A. Levin, C. N. Jiang, T. Stein, D. A. Gajewski, S. H. Han, and M. B. Maple, "Normal-State Out-of-Plane and In-Plane Resistivities of Y1-xPrxBa2Cu3O7-d (0calmasan@physics.kent.edu.

L. Ammor, J. C. Soret, A. Smina, V. Ta Phuoc, A. Ruyter, A. Wahl, B. Martinie, J. Lecomte, and Ch. Simon, "Dimensional Crossover Vortex Fluctuations in Irreversibility Line of High-Quality Tl2Ba2CaCu2O8 Thin Film." Submitted to 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. Laboratoire d'Electrodynamique des Materiaux Avances, Universite F. Rabelais, UFR Sciences, Parc de Grandmont, F-37200 Tours, FRANCE.

I. Aranson, L. Tsimring, and V. Vinokur, "Evolution on a Rugged Landscape: Pinning and Aging." 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.

Howard A. Blackstead and John D. Dow, "Are all High-Temperature Superconductors p-type?" Department of Physics, University of Notre Dame, Notre Dame, IN 46556; telephone (219) 631-7078; telefax (219) 631- 5952; e-mail blackstd@rems1.phys.nd.edu.

Howard A. Blackstead and John D. Dow, "Crystal-Field and Size Effects in (Rare-Earth)2-zCezCuO4 Superconductivity." Department of Physics, University of Notre Dame, Notre Dame, IN 46556; telephone (219) 631- 7078; telefax (219) 631-5952; e-mail blackstd@rems1.phys.nd.edu.

T. Boeske, O. Knauff, R. Neudert, M. Kielwein, M. Knupfer, M. S. Golden, J. Fink, H. Eisaki, S. Uchida, K. Okada, and A. Kotani, "High Energy Spectroscopic Studies of Single Crystalline Sr2CuO2Cl2." Submitted to Phys. Rev. B. Institut fuer Festkoerper- und Werkstofforschung Dresden, Postfach 270016, D-01171 Dresden, GERMANY. 74.72.Jt; 82.80.Pv.

G. Boettger, H. Schwer, E. Kaldis, and K. Bente, "Ca Doping of YBa2Cu3O7-d Single Crystals: Structural Aspects." To be published in Physica C (in press). Laboratorium fuer Neutronenstreuung, Eidgenoessische Technische Hochschule Zurich and Paul Scherrer Institut, CH-5232 Villigen PSI, SWITZERLAND; telefax +41 56 310 2939; e-mail grit.boettger@psi.ch. Key words: structure of YBa2Cu3O7-d, Ca doping, x-ray single-crystal structure analysis.

G. Brandstaetter, C. Boehmer, H. W. Weber, and B. W. Veal, "Experimental Study of the Lower Critical Field in High-Tc 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. Atominstitut der OEsterreichischen Universitaeten, Schuettelstrasse 115, A-1020 Wien, AUSTRIA.

G. Brandsaetter, A. Vostner, H. W. Weber, T. Chattopadhyay, R. Cubitt, H. Fischer, and G. A. Emel'chenko, "Neutron Diffraction by the Flux Line Lattice in YBa2Cu3O7-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. Atominstitut der OEsterreichischen Universitaeten, Schuettelstrasse 115, A-1020 Wien, AUSTRIA.

V. Chechersky, M. Gal, Zoltan Homonnay, Gy. Vanko, E. Kuzmann, S. Tyagi, R. L. Greene, A. Vertes, and A. Nath, "Lattice Dynamics of Y0.9Pr0.1Ba2Cu3O7-d." To be published in Physica C. Contact A. Nath, Department of Chemistry, Drexel University, Philadelphia, PA 19104; telephone (215) 895-2648; telefax (215) 895-1265; e-mail amar_nath@coasmail.drexel.edu.

F. Chen, Q. M. Lin, Y. Y. Xue, and C. W. Chu, "Thermopower of HgBa2Cam- 1CumO2m+2+d Under Pressure." 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. 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.

A. Crisan, L. Miu, S. Popa, and C. Beduz, "Field and Temperature Dependence of the Current-Voltage Characteristics of Bi2Sr2Ca2Cu3O10/Ag Multifilamentary Tapes." Submitted to J. Supercond. Institute of Cryogenics, University of Southampton, Southampton SO17 1BJ, UNITED KINGDOM; telefax +44 1703 59 30 53. Key words: multifilamentary tapes, I-V curves, flux creep, collective pinning.

A. Crisan, L. Miu, S. Popa, Y. Yang, and C. Beduz, "Current-Voltage Characteristics of Bi2Sr2Ca2Cu3O10+x/Ag Multifilamentary Tapes in Zero Applied Magnetic Field." Submitted to Supercond. Sci. Technol. Institute of Cryogenics, University of Southampton, Southampton SO17 1BJ, UNITED KINGDOM; telefax +44 1703 59 30 53.

Daniel Duffy, Alexander Nazarenko, Stephan Haas, Adriana Moreo, Jose Riera, and Elbio Dagotto, "Hole Doping Evolution of the Quasiparticle Band in Models of Strongly Correlated Electrons for the High-Tc Cuprates." Submitted to Phys. Rev. B. National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32306-4005; telephone (904) 644-0530. 74.20.-z; 74.20.Mn; 74.25.Dw.

B. J. Feenstra, F. C. Klaassen, D. van der Marel, Z. H. Barber, R. Perez Pinaya, and M. Decroux, "Characterization of Superconducting Thin Films Using mm-Wave Transmission." Submitted to the Proceedings of the SPIE Conference, Denver, 1996. Materials Science Center, Laboratory of Solid State Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen, THE NETHERLANDS; D. van der Marel's telephone +31 50 363-7229 or -4826; telefax +31 50 363-4825; e-mail marel@phys.rug.nl. Key words: superconducting thin film, mm-wave transmittion, conductivity, penetration depth.

B. J. Feenstra, F. C. Klaassen, D. van der Marel, Z. H. Barber, R. Perez Pinaya, and M. Decroux, "Penetration Depth and Conductivity of NbN and DyBa2Cu3O7-d Thin Films Measured by mm-Wave Transmission." Submitted to Physica C. Materials Science Center, Laboratory of Solid State Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen, THE NETHERLANDS; D. van der Marel's telephone +31 50 363-7229 or -4826; telefax +31 50 363-4825; e-mail marel@phys.rug.nl.

S. Fujihara, N. Yoshida, and T. Kimura, "Preparation of 94 K Superconducting NdBa2Cu3O7-d Without Post-Anneal in Oxygen." To be published in Physica C (in press). Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223, JAPAN; telefax +81 45 562 7625. Key words: NdBa2Cu3O7-d, Ba2Cu3O5+x, sol-gel, magnetization, critical current density. 74.60.Jg.

A. Gerber, A. Milner, A. Voronel, A. Rubstein, Yu. Rosenberg, and M. P. Macht, "Superconductivity in the Metallic Amorphous Alloy Zr41.2Ti13.8Cu12.5Ni10Be22.5." To be published in Physica C (in press). School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, 69978 Tel Aviv, ISRAEL. Key words: superconductivity, metallic glass, Zr41.2Ti13.8Cu12.5Ni10Be22.5.

Mark S. Golden, Heike C. Schmelz, Martin Knupfer, Stefan Haffner, Gernot Krabbes, Joerg Fink, Victor Yu. Yushankhai, Helge Rosner, Roland Hayn, Andreas Mueller, and Gerd Reichardt, "The Dispersion of a Hole in a Two- Dimensional Cu3O4 Plane: a Tale of Two Singlets." Submitted to Phys. Rev. Lett. Institute for Solid State and Materials Research (IFW) Dresden, P.O. Box 270016, D-01171 Dresden, GERMANY. 71.20.-b; 74.25.Jb; 79.60.-i.

S. N. Gordeev, P.A.J. de Groot, M. Oussena, R. M. Langan, A. P. Rassau, R. Gagnon, and L. Taillefer, "Organization of Vortex Motion in Detwinned YBa2Cu3O7-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. Department of Physics, University of Southampton, Highfield, Southampton, Hampshire, SO17 1BJ, UNITED KINGDOM; R. M. Langan's telephone +44 1703 592058; telefax +44 1703 593910; e-mail rml@phys.soton.ac.uk.

B. Grevin, Y. Berthier, F. Pourtier, J. C. Villegier, and U. Schmatz, "NQR: A Non-Destructive Method for Studying Oxygen Content and Defects in YBa2Cu3O6+x Superconducting Thin Films." To be published in Physica C (in press). Laboratoire de Spectrometrie Physique, Universite Joseph Fourier Grenoble 1, BP 87, F-38402 Saint-Martin d'Heres Cedex, FRANCE; telefax +33 4 7651 45 44; e-mail grevin@spectro.grenet.fr. Key words: NQR, thin films, YBCO, HTSC. 74.72.Bk; 74.76.Bz; 76.60.Gv.

U. Gunsenheimer and A. D. Zaikin, "Ballistic Transport in Superconducting Weak Links in a Microwave Field." Fakultaet fuer Physik und Astronomie, Lehrstuhl fuer Theoretische Festkoerperphysik, Ruhr- Universitaet Bochum, D-44780 Bochum, GERMANY; e-mail uweg@uweg.tp3.ruhr- uni-bochum.de; preprint also available at cond-mat@xxx.lanl.gov (#9612135). 74.40.+k; 74.50.+r; 74.80.Fp.

M. Gustafsson, E. Olsson, H. R. Yi, D. Winkler, and T. Claeson, "Grain Boundary Evolution of YBa2Cu3O7-d in the Vicinity of Steps on Patterned (001) LaAlO3 Substrates." To be published in Appl. Phys. Lett. Department of Physics, Chalmers University of Technology, S-412 96 Goeteborg, SWEDEN; telephone +46 31 7723322; telefax +46 31 7723224; e- mail marcia@fy.chalmers.se.

Damian P. Hampshire, "Magnetic Properties of the Flux Line Lattice in Paramagnetic Superconductors." To be published in J. Phys. C. Superconductivity Group, Department of Physics, University of Durham, South Road, Durham DH1 3LE, UNITED KINGDOM; telephone +44 191 374 2167; telefax +44 191 374 3749. 74.70.Ad; 74.25.Ha.

G. Samadi Hosseinali, H. W. Weber, E. Stangl, S. Proyer, and D. Baeuerle, "Flux Pinning in Oxygen Deficient YBa2Cu3O7-d Thin Films." Submitted to 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. Atominstitut der OEsterreichischen Universitaeten, A-1020 Wien, AUSTRIA.

Wen-Jye Jang, Hatsumi Mori, Masaya Watahiki, Setsuko Tajima, Naoki Koshizuka, and Shoji Tanaka, "Change in Crystal Structure and Electron Density by Introducing Oxygen in YBa2Cu3Oy Single Crystal." Preprint #N96457; to be published in J. Solid State Chem. 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: YBCO superconductor, electron density, tetragonal YBa2Cu3O6 crystal, crystal structure.

M. Jiang, M. T. Lanagan, and K. C. Goretta, "Microstructure and Properties of Tl0.75Bi0.25Sr1.6Ba0.4Ca2Cu3Ox Tapes." Submitted to Appl. Supercond. 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. Jiang, N.-C. Yeh, C.-C. Fu, M. Konczykowski, and F. Holtzberg, "Investigation of the Current-Induced Nonlinear Vortex Dynamics in YBa2Cu3O7 Single Crystals Using Transport and Transmittivity Measurements." 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. Department of Physics, California Institute of Technology, Pasadena, CA 91125.

W. Jiang, N.-C. Yeh, T. A. Tombrello, A. P. Rice, and F. Holtzberg, "Current-Driven Vortex Dynamics in Untwinned YBa2Cu3O7 Superconducting Single Crystals." Submitted to J. Phys. Department of Physics, California Institute of Technology, Pasadena, CA 91125.

U. Kabasawa, H. Hasegawa, T. Fukazawa, Y. Tarutani, and K. Takagi, "Electric Field Effect on the Transport Properties of Ultrathin Y0.9Pr0.1Ba2Cu3Oy Channels in the Insulating-Phase of Superconductor- Insulator Transition." To be published in J. Appl. Phys. Electronic Device Manufacturing, Equipment & Engineering Division, Hitachi, Ltd., 6 Kanda-Surugadai 4-chome, Chiyoda-ku, Tokyo 101, JAPAN; telefax +81 3 5294 2009; e-mail kaba@cm.head.hitachi.co.jp.

A. P. Kampf and T. P. Devereaux, "Extended Impurity Potential in a d_[x^2-y^2] Superconductor." Submitted to Phys. Rev. Lett. Institut fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Str. 77, D- 50937 Koeln, GERMANY; e-mail apk@thp.uni-koeln.de; preprint also available at cond-mat@xxx.lanl.gov (#9701170).

S. M. Kazakov, S. Pachot, E. M. Kopnin, S. N. Putilin, E. V. Antipov, C. Chaillout, J. J. Capponi, P. G. Radaelli, and M. Marezio, "Synthesis, Neutron Diffraction Study and Cation Substitutions in Srn-1Cun+1O2n (n=3,5)." To be published in Physica C (in press). Contact C. Chaillout, Laboratoire de Cristallographie, CNRS-UJF, BP 166, F-38042 Grenoble Cedex 9, FRANCE; telefax +33 76 88 1038; e-mail chaillout@labs.polycnrs-gre.fr.

JunHo Kim and Dojun Youm, "Growth of Textured c-Axis Normal Y1Ba2Cu3O7-d Thin Films on Yttria-Stabilized Zirconia Substrates with Crystalline Axes Tilted with Respect to the Surfaces." To be published in Physica C (in press). Contact Dojun Youm, Department of Physics, Korea Advanced Institute of Science and Technology, Kusong-Dong, Yusung-Gu, Taejon 305- 107, KOREA; telefax +82 42 869 2510; e-mail djyoum@sorak.kaist.ac.kr. 74.76.Bz.

Richard A. Klemm, "Why We Still Don't Know the Symmetry of the Order Parameter in High Temperature Superconductors." To be published in the Proc. of the Int. Workshop on High-Temp. Supercond.: Ten Years After its Discovery, Jaipur, India, Dec. 16-21, 1996, edited by S. M. Bose and K. B. Garg (Narosa Publishing House, New Delhi). Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; e-mail richard_klemm@qmgate.anl.gov).

M. Knupfer, R. Neudert, M. Kielwein, S. Haffner, M. S. Golden, J. Fink, C. Kim, Z.-X. Shen, M. Merz, N. Motoyama, H. Eisaki, S. Uchida, Z. Hu, M. Domke, and G. Kaindl, "Site Specific Unoccupied Electronic Structure of One-Dimensional SrCuO2." To be published in Phys. Rev. B. Institut fuer Festkoerper- und Werkstofforschung Dresden, D-01171 Dresden, GERMANY.

V. N. Kushnir, C. Coccorese, S. L. Prischepa, and M. Salvato, "Flux Creep Flux Flow Crossover in Disordered Superconductors." To be published in Physica C (in press). Contact C. Coccorese, Dipartimento di Fisica and INFM, Universita Degli Studi di Salerno, Baronissi (Sa), I-84081, ITALY; telefax +39 89 953 804; e-mail coccorese@vaxsa.csied.unisa.it. Key words: pinning energy, statistical distribution, critical current. 74.60.Ge; 74.60.Jg.

A. L. Kuzemsky, "Quasiparticle Many-Body Dynamics of Highly Correlated Electronic Systems." Preprint #E17-96-312; presented at the 20th Intl. School on Theoretical Physics, Ustron, Poland, Sept. 1996. Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, RUSSIA; telefax +7 095 975 23 81; e-mail kuzemsky@thsun1.jinr.dubna.su.

W.-K. Kwok, J. A. Fendrich, V. M. Vinokur, A. E. Koshelev, and G. W. Crabtree, "Reply to Comment of Grigera et al." 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.

Theodora Leventouri, "A New Method for Measuring the Degree of Preferred Orientation in Bulk Textured YBa2Cu3Ox." To be published in Physica C. Department of Physics, Florida Atlantic University, Boca Raton, FL 33431; telephone (407) 367-2695; telefax (407) 367-2662; e-mail leventou@acc.fau.edu. Key words: grain alignment (texturing), bulk textured superconductors.

S. Li, M. Bredehoeft, Q. Y. Hu, H. K. Liu, S. X. Dou, and W. Gao, "The Effect of Annealing and Mechanical Deformation on the Grain Alignment of (Bi,Pb)2Sr2Ca2Cu3O8+x Superconductors." To be published in Physica C (in press). Contact W. Gao, Department of Chemical and Materials Engineering, University of Auckland, Auckland, NEW ZEALAND; telefax +64 9 373 7463. Key words: processing and microstructure of superconductors, grain alignment.

Y. P. Li, J. R. Liu, X. T. Cui, Y. Cao, Z. J. Qu, Q. Y. Chen, C. W. Chu, and W. K. Chu, "On the Role of Ag in Improved YBa2Cu3O7-d Films." Preprint #97:011; 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. 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.

F. A. List, D. M. Kroeger, and V. Selvamanickam, "Hysteresis of the Transport Critical Current of (Tl, Pb)-(Sr,Ba)-Ca-Cu-O and Bi-Sr-Ca-Cu-O Conductors: Effects of Temperature and Magnetic Field." To be published in Physica C (in press). Metals and Ceramics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6116; telefax (423) 574-7659. Key words: critical current density, granular superconductivity, grain boundaries, penetration depth.

D. V. Livanov, A. A. Varlamov, and F. Federici, "Thermoelectric Effect in High-Tc Superconductors: The Role of Density of States Fluctuations." Moscow Institute for Steel and Alloys, Leninsky Prospect 4, 117936 Moscow, RUSSIA.

Ricardo P.S.M. Lobo, Francois Gervais, and S. B. Oseroff, "The Strange Infrared Conductivity of La2CuO4.06." To be published in Europhys. Lett. Bldg. 725D, National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY 11973; telefax (516) 344-3238; e-mail lobo@bnl.gov. 71.38.+i; 74.25.Gz; 78.30.-j.

T. R. Lu and Teng-Ming Chen, "Structural and Superconducting Properties of Phases in the Underdoped Y2(Ba1-xSrx)4Cu7O14+d System: Evidence for a Chemical Pressure Effect." To be published in Physica C (in press). Contact Teng-Ming Chen, Department of Applied Chemistry, National Chiao- Tung University, Hsinchu, Taiwan 300, REPUBLIC OF CHINA. Key words: high-pressure synthesis; underdoped Y2(Ba1-xSrx)4Cu7O14+d, Rietveld refinement, electrical resistivity, chemical pressure effect.

O. V. Misochko and E. Ya. Sherman, "Van Hove Singularity in Raman Scattering in High-Tc Superconductors: Experimental Observation and Mechanism Analysis of Electronic and Phonon Raman Processes." Preprint #N 14/97. Contact E. Ya. Sherman, Department of Theoretical Physics, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow Region, RUSSIA; e-mail sher@theor.op.mipt.ru.

E. Morre, S. A. Grigera, E. Osquiguil, G. Nieva, and F. de la Cruz, "Angular Restrictions on the Glass Transition and the c-Axis Correlated Liquid Phase in Twinned YBa2Cu3O7-d." Submitted to Phys. Rev. Lett. Laboratorio de Bajas Temperaturas, Centro Atomico Bariloche, 8400 S.C. de Bariloche, ARGENTINA; e-mail eckhart@cab.cnea.edu.ar.

Cornelia Mueller, Peter Majewski, Guenter Thurn, and Fritz Aldinger, "Processing Effects on Mechanical and Superconducting Properties of Bi2201 and Bi2212 Glass Ceramics." To be published in Physica C (in press). Pulvermetallurgisches Laboratorium, Institut fuer Werkstoffwissenschaft, Max-Planck-Institut fuer Metallforschung, Heisenbergstrasse 5, D-70569 Stuttgart, GERMANY; telefax +49 711 6861 131; e-mail cmueller@aldix.mpi-stuttgart.mpg.de. Key words: high-Tc superconductor, Bi-Sr-Ca-Cu-O system, crystallization, glass ceramics, deformation.

Hisashi Nagai, Yutaka Yoshida, Yoshiaki Ito, Satoshi Taniguchi, Izumi Hirabayashi, Noriaki Matsunami, and Yoshiaki Takai, "Preparation of YBa2Cu3O7-y Films by Metal Organic Chemical Vapor Deposition Using Liquid State Nonfluorinated Sources." Preprint #N96298; to be published in Supercond. Sci. Tech. Department of Electrical Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-01, JAPAN; telephone +81 52 789 3908; telefax +81 52 789 3441. 74.76.-w.

M. R. Norman, H. Ding, J. C. Campuzano, T. Takeuchi, M. Randeria, T. Yokoya, T. Takahashi, T. Mochiku, and K. Kadowaki, "Bosonic Mode Mixing in the Superconducting State Spectral Function of Bi2Sr2CaCu2O8+d." MSD-223, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439; telephone (630) 252-3518; telefax (630) 252-7777; e-mail norman@thio.msd.anl.gov. 71.25.Hc; 74.25.Jb; 74.72.Hs; 79.60.Bm.

X. Oudet, "About the Valence." Laboratoire de Magnetisme et d'Optique de l'Universite de Versailles, C.N.R.S., 45 Avenue des Etats-Unis, F- 78035 Versailles, FRANCE; e-mail xavier.oudet@physique.uvsq.fr.

Itai Panas and Refael Gatt, "How Repulsive are Holes to Local Antiferromagnetic Order in the Cuprates: A Quantum Chemical Cluster Study." Submitted to Chem. Phys. Lett. Department of Inorganic Chemistry, Goeteborg University, S-412 96 Goeteborg, SWEDEN; telephone +46 31 7722861; telefax +46 31 7722853; e-mail itai@inoc.chalmers.se.

Itai Panas and Refael Gatt, "On Superconductivity in (Sr,Ca)14Cu24O41: Towards a Chemical Standard Model." Submitted to Chem. Phys. Lett. Department of Inorganic Chemistry, Goeteborg University, S-412 96 Goeteborg, SWEDEN; telephone +46 31 7722861; telefax +46 31 7722853; e- mail itai@inoc.chalmers.se.

L. M. Paulius, J. A. Fendrich, W.-K. Kwok, A. E. Koshelev, V. M. Vinokur, G. W. Crabtree, and B. G. Glagola, "Effects of 1 GeV Uranium Ion Irradiation on Vortex Pinning in Single Crystals of the High Temperature Superconductor YBa2Cu3O7-d." 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. 61.80.Jh; 74.60.Ge; 74.60.-w; 74.72.-h; 74.72.Bk.

D. Pedron, G. Visentini, R. Bozio, Jack M. Williams, and John A. Schlueter, "Phonon Dynamics and Superconductivity in the Organic Crystal kappa-(BEDT-TTF)2Cu[N(CN)2]Br." To be published in Physica C (in press). Department of Physical Chemistry, University of Padova, Via Loredan 2, I-35131 Padova, ITALY; telefax at Argonne, IL (630) 252-9151. Key words: electron-phonon coupling, organic superconductor, phonon spectrum, Raman scattering.

V. Ta Phuoc, J. C. Soret, L. Ammor, A. Ruyter, B. Martinie, A. Wahl, J. Lecomte, and Ch. Simon, "A Comparative Study of the Superconducting Transition in Tl-2212 Polycrystals and Granular Thin Films." Submitted to 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. Laboratoire d'Electrodynamique des Materiaux Avances, Universite F. Rabelais, UFR Sciences, Parc de Grandmont, F-37200 Tours, FRANCE.

V. B. Podobedov, J. P. Rice, A. Weber, and H. D. Drew, "Raman Scattering from Single Crystal YBa2Cu3O7-d in a Magnetic Field." To be published in J. Supercond. Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-0001; A. Weber's telephone (301) 975-2377; telefax (301) 975-3038; e-mail aweber@tiber.nist.gov. Key words: YBCO, Raman scattering, magnetic field.

A. V. Pop, R. Deltour, D. Ciurchea, A. Harabor, Gh. Ilonca, and S. Coldea, "Activation Energies in the Vortex Liquid State of Bulk (Bi1.6Pb0.4)(Sr1.8Ba0.2)Ca2Cu3Oy Superconductor." To be published in Int. J. Mod. Phys. Faculty of Physics, "Babes-Bolyai" University, 3400 Cluj-Napoca, ROMANIA.

L. Porcar, D. Bourgault, J. M. Barbut, M. Barrault, P. Germi, and R. Tournier, "High Critical Transport Currents of Melt Textured YBCO up to 6000 A." To be published in Physica C (in press). Elaboration par Procedes Magnetiques - Matformag, CNRS, 25 Avenue des Martyrs, BP 166, F-38042 Grenoble Cedex 09, FRANCE; telefax +33 7688 1280; e-mail bourg@labs.polycnrs-gre.fr. 74.60.Jg; 81.10.-h; 81.40.Rs.

A. K. Pradhan, B. Chen, G. Pindoria, K. Nakao, N. Koshizuka, D. Kanjilal, A.J.S. Chowdhury, and B. M. Wanklyn, "Influence of Columnar Defects on Magneto-Transport and Magnetization Properties of Bi2Sr2CaCu2O8+y." To be published in Phys. Rev. B (in press). Superconductivity Research Laboratory, International Superconductivity Technology Center (ISTEC), 10-13 Shinonome 1-chome, Koto-ku, Tokyo 135, JAPAN; telephone +81 3 3536-5703 through -5705; telefax +81 3 3536-5714 or -5717; B. Chen's e-mail bc@crisscross.com. 74.60.Ge; 74.60.Jg; 74.25.Fy.

A. K. Pradhan, S. B. Roy, G. Pindoria, P. Chaddah, D. Kanjilal, N. Koshizuka, C. Chen, and B. M. Wanklyn, "Flux Pinning by Columnar Defects in Bi2Sr2CaCu2O8+y Crystals." To be published in the Proc. of the 9th Int. Symp. on Supercond. (ISS'96), Sapporo, Hokkaido, Japan, Oct. 21-24, 1996. 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: heavy-ion irradiation, columnar defects, flux pinning.

X. D. Qiu, Q. Xiong, L. Gao, Y. Y. Xue, and C. W. Chu, "Pressure Dependence of Tc in HgBa2CuO4+d up to 18 GPa with 0.17 < delta < 0.3." Preprint #97:012; 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. 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.

Edson Sardella, "Coexistence of Different Types of Vortex Lines in Anisotropic Superconductors." To be published in Physica C (in press). Departamento de Fisica, Universidade Estadual Paulista, Caixa Postal 473, 17033-360 Bauru-SP, BRAZIL; telefax +55 14 230 4470; e-mail sardella@azul.bauru.unesp.br. 74.60.Ec; 74.60.Ge.

F. M. Sauerzopf, M. Werner, H. W. Weber, R. A. Suris, D. V. Kulikov, V. S. Kharlamov, and Yu. V. Trushin, "Small Defects in YBCO Single Crystals: Tc after Neutron Irradiation and Annealing." 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. Atominstitut der OEsterreichischen Universitaeten, A-1020 Vienna, AUSTRIA.

J. Schuetzmann, H. S. Somal, A. A. Tsvetkov, D. van der Marel, G.E.J. Koops, N. Koleshnikov, Z. F. Ren, J. H. Wang, E. Brueck, and A. A. Menovsky, "Experimental Test of the Inter-Layer Pairing Models for High- Tc Superconductivity Using Grazing Incidence Infrared Reflectometry." Submitted to Phys. Rev. B. Materials Science Centre, Laboratory of Solid State Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen, THE NETHERLANDS; D. van der Marel's telephone +31 50 363-7229 or -4826; telefax +31 50 363 4825; e-mail marel@phys.rug.nl. 74.25.Gz; 78.30.Er; 71.45.Gm; 74.25.Nf.

C. Sekar, A. Thamizhavel, and C. Subramanian, "Effect of Degradation on Surface and Mechanical Properties of C60 and C60/C70 Single Crystals." To be published in Physica C (in press). Contact C. Subramanian, Crystal Growth Centre, Anna University, Madras 600 025, INDIA; telefax +91 44 235 2774; e-mail crystal@sirnetm.ernet.in.

Z.-X. Shen and J. R. Schrieffer, "Momentum Temperature and Doping Dependence of Photoemission Lineshape and Implications for the Nature of the Pairing Potential in HTS Materials." To be published in Phys. Rev. Lett. Department of Applied Physics and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, CA 94305. 79.60.Bm; 73.20.Dx; 74.62.Dh; 74.72.Hs.

E. Sherman, "Phonon-Induced Changes of the t-J Model Parameters: Charge Fluctuations Approach." Submitted to Solid State Commun. Department of Theoretical Physics, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow Region, RUSSIA; e-mail sher@theor.op.mipt.ru. Key words: high-Tc superconductors, electron-phonon interactions, spin dynamics.

E. Silva, M. Lanucara, and R. Marcon, "Microwave Surface Resistance Peak at Tc in Bi2Sr2CaCu2O8+x Film." To be published in Physica C (in press). Dipartimento di Fisica "E. Amaldi", Universita degli Studi "Roma Tre" and INFM, Via della Vasca Navale 84, I-00146 Rome, ITALY; telefax +39 6 557 9303; e-mail silva@amaldi.fis.uniroma3.it. 74.25.Nf; 74.76.Bz; 84.40.Cb.

C. Morais Smith, A. O. Caldeira, and G. Blatter, "Relaxation Rates of Flux-Lines and Flux-Pancakes in the Presence of Correlated Disorder." To be published in Physica C (in press). I Institut fuer Theoretische Physik, Universitaet Hamburg, D-20355 Hamburg, GERMANY; e-mail smith@physnet.uni-hamburg.de. Key words: flux creep, irradiation effect, Hall effect.

J. C. Soret, V. Ta Phuoc, L. Ammor, A. Ruyter, B. Martinie, A. Wahl, J. Lecomte, and Ch. Simon, "Superconducting Transition in Tl-2212 Thin Films and Polycrystals: Effect of the Dimensionality of the Sample." To be published in Solid State Commun. Laboratoire d'Electrodynamique des Materiaux Avances, Universite F. Rabelais, UFR Sciences, Parc de Grandmont, F-37200 Tours, FRANCE.

S. Srinivas, A. K. Bhatnagar, S. B. Ogale, and R. D. Vispute, "Studies on YBa2Cu4O8 Thin Films." To be published in Physica C (in press). School of Physics, University of Hyderabad, Hyderabad 500 046, INDIA.

T. Stein, G. A. Levin, C. N. Jiang, C. C. Almasan, D. A. Gajewski, S. H. Han, and M. B. Maple, "Flux Motion in Underdoped Y1-xPrxBa2Cu3O7-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 C. 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.

Setsuko Tajima, "An Optical Spectroscopic View on the Mechanisms of High-Tc Superconductivity." To be published in Supercond. Rev. 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: high-Tc superconductivity, optical properties, strong electron correlation, anisotropy, metal-insulator transition.

A. Thamizhavel, D. Prabhakaran, R. Jayavel, and C. Subramanian, "Growth and Characterization of Superconducting Bi2Sr2Ca(1-x)CexCu2O8+d Single Crystals." To be published in Physica C (in press). Contact C. Subramanian, Crystal Growth Centre, Anna University, Madras 600 025, INDIA; telefax +91 44 235 2774; e-mail crystal@sirnetm.ernet.in.

S. Tirumala, D. F. Lee, D. M. Kroeger, and K. Salama, "Thermomechanical Processing and Reaction Kinetics of Bi-2223 Powder-In-Tube Tapes Made from Aerosol Precursor." Preprint #97:013; submitted to Supercond. Sci. & Technol. 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.

D. van der Marel and A. Tsvetkov, "Transverse Optical Plasmons in Layered Superconductors." Presented at the XXI Int. Conf. on Low Temp. Phys. (LT21), Prague, Czech Republic, Aug. 8-14, 1996; to be published in Czech. J. Phys., Vol. 46 (1996). Solid State Physics Laboratory, University of Groningen, Nijenborgh 4, 9747 AG Groningen, THE NETHERLANDS; telephone +31 50 363-7229 or -4826; telefax +31 50 363 4825; e-mail marel@phys.rug.nl.

V. K. Vlasko-Vlasov, U. Welp, G. W. Crabtree, D. Gunter, V. Kabanov, and V. I. Nikitenko, "'Meisner Holes' in Superconductors." 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.

J.Y.T. Wei, C. C. Tsuei, P.J.M. van Bentum, Q. Xiong, C. W. Chu, and M. K. Wu, "Quasiparticle Tunneling Gap-Spectra of the High-Tc Mercury- Cuprates: Implications of the d-Wave 2D Van Hove Scenario." Submitted to Phys. Rev. B. Department of Physics, California Institute of Technology, Pasadena, CA 91125. 74.50.+r; 74.72.Jt; 74.76.Bz; 74.25.Jb; 74.20.Fg.

W. C. Wu, W. A. Atkinson, and J. P. Carbotte, "c-Axis Transport in Bilayer Cuprates and Relation to Pseudogap." Submitted to Phys. Rev. B. Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, CANADA L8S 4M1. 74.80.Dm; 78.30.-j; 74.25.Jb; 74.72.-h.

N.-C. Yeh, W. Jiang, C. C. Fu, M. Konczykowski, and F. Holtzberg, "Intrinsic and Disorder-Induced Anisotropic Vortex Dynamics of 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. Department of Physics, California Institute of Technology, Pasadena, CA 91125.

N.-C. Yeh, U. Kriplani, W. Jiang, J. Kumar, H. F. Fong, D. S. Reed, and C. C. Tsuei, "High-Frequency Vortex Critical Dynamics of Superconducting Amorphous Mo3Si Films." Submitted to Int. J. Mod. Phys. B. Department of Physics, California Institute of Technology, Pasadena, CA 91125. 74.60.Ec; 74.25.Nf; 74.60.Ge; 74.76.Db.

P. Yossefov, G. E. Shter, G. M. Reisner, A. Friedman, Y. Yeshurun, and G. S. Grader, "Relationship of Solubility Parameter (x), Powder Properties and Phase Formation in the Nd1+xBa2-xCu3O6.5+x/2+d System." To be published in Physica C (in press). Department of Chemical Engineering, Crown Center for Superconductivity, Technion, Haifa 32000, ISRAEL. Key words: superconductor, Nd1+xBa2-xCu3O6.5+x/2+d, solid solution, phase formation.

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

March 31 - April 4, 1997: 1997 MRS Spring Meeting, San Francisco Marriott, San Francisco, CA. Meeting will feature 28 symposia covering a broad range of materials science and engineering as well as processing topics. Includes symposium on superconductivity. Array of tutorials and major exhibits will complement the technical program. For further information, contact the Materials Research Society, Meetings Department, 9800 McKnight Road, Pittsburgh, PA 15237-6006; telephone (412) 367-3003; telefax (412) 367-4373; e-mail stevens@mrs.org.

April 14 - 18, 1997: Workshop on Soft & Particle Materials, International Centre of Condensed Matter Physics, Universidade de Brasilia, Brasilia DF, Brazil. Topics to be covered include: transport in disordered systems, aggregation, sedimentation, segregation, experiments on granular material, growth instabilities, granular flow. Abstract deadline, March 20, 1997. For information, contact Workshop on Soft & Particle Materials, Centro Internacional de Fisica da Materia Condensada, Universidade de Brasilia, Caixa Postal 04513 - 70919-970 Brasilia DF, Brazil; telephone +55 61 348-2572; telefax + 55 61 273- 3884; e-mail info@iccmp.br; additional information available through gopher.iccmp.br or Web site http://www.iccmp.br.

May 4 - 7, 1997: The 1997 International Convention and Exposition on High Speed Ground Transportation, Bally's Casino Resort, Las Vegas, NV. For information, contact High Speed Ground Transport Association, 938 Penn Avenue, Suite 703, Pittsburgh, PA 15222; telephone (412) 281-6636.

*May 25 - 28, 1997: International Workshop on Tl and Hg Based Superconducting Materials, University Centre, University of Cambridge, United Kingdom. Objective is to provide a comprehensive overview of research and development activities in these materials. Main topics include: processing, physical properties, critical currents and microstructure of single crystals, thick and thin films, and wires and tapes. About twenty invited lectures, and oral and poster papers. Proceedings to be published. For further information, contact Shiming Wu, IRC in Superconductivity, University of Cambridge, Cambridge CB3 0HE, United Kingdom; telefax +44 1223 33 7074; e-mail sw204@cus.cam.ac.uk; Web site http://www.sucon.cam.ac.uk/workshops/iwtlhg.html.

*June 8 - 13, 1997: 1997 IEEE MTT-S International Microwave Symposium, Denver, CO. Will focus on highly integrated ICs or subsystems that include RF functions at any frequency. Symposium W: Superconducting Technology: Superconducting microwave and millimeter-wave circuits and systems. For further information, contact Vijay Nair, Technical Program Chair; telephone (602) 413-5922; telefax (602) 413-5934; e-mail v.nair@ieee.org. For latest information, see Web page at http://www.ieee.org/mtt/mtt.html.

*June 15 - 18, 1997: Third Joint ISTEC/MRS International Workshop on Superconductivity: Suitable Materials and Processing for HTS Applications Towards the Next Decade, The Royal Waikoloan, Big Island, Hawaii. Will mainly be a single-session meeting with significant time allotted to encouraging the exchange of information among participants. Regular session titles are: processing of HTS bulk; processing of HTS wire, tapes, and thick films; crystal growth related to HTS processing of bulk and films; thin-film processing for rf applications; and fabrication and control of HTS junctions for digital circuits. Rump sessions: ac losses, vortex dynamics, and pinning; and SQUID and sensor applications. Invited and contributed oral presentations and posters. Contact Koji Kajimura, Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba, Ibaraki 305, Japan, telephone +81 298 54-5003, telefax +81 298 54-5070, e-mail kajimura@etl.go.jp; or Eric Hellstrom, Department of Materials Science & Engineering, University of Wisconsin at Madison, Madison, WI 53706, telephone (608) 263-9462, telefax (608) 263-1087.

*June 26 - 29, 1997: Superconducting Materials Aspects : Research & Technology (SMART 97), Liege, Belgium. A satellite to the Third European Conference on Applied Superconductivity (EUCAS'97) to be held at Veldhoven, The Netherlands (June 30 - July 3, 1997). Topics will include phase chemistry and processing of bulk and thick-film materials, crystal-growth processes, relationship between material structure and properties, and applications. Abstract deadline, March 1, 1997. For information, contact Chantal Lacrosse or Michele Delville, Conference Secretaries, AIM rue St. Gilles 31, B-4000 Liege, Belgium; telephone +32 4 222 2946; telefax +32 4 222 2382; e-mail aimulg@misc.ulg.ac.be.

July 14 - 25, 1997: IX Trieste Workshop on Open Problems in Strongly Correlated Systems, Miramare, Trieste, Italy. Special focus on the interface between mesoscopia, strong electron correlations, and symmetry breaking. Workshop will strongly encourage informal interactions and only two formal talks per day will be scheduled, reviewing experimental and theoretical issues of particular interest. Topics include: ransport and mesoscopics in strongly correlated systems, the interface between methods and approaches in mesoscopic and strongly correlated systems, non-Fermi-liquid physics, low-dimensional conductors, heavy fermion and cuprate systems, and new materials. Participation is open to scientists from all countries that are members of the UN, UNESCO or IAEA. Application deadline, March 31, 1997. Contact IX Trieste Workshop on Strongly Correlated Systems, International Centre for Theoretical Physics, P.O. Box 586, I-34100 Trieste, Italy; telephone +39 40 224 0111; telefax +39 40 224 163; e-mail smr1001@ictp.trieste.it. (The "Request for Participation" form is available at this e-mail address by typing "get index" on subject line. Also available at Web site http://www.ictp.trieste.it/.)

Aug. 31 - Sept. 5, 1997: Fullerenes: Chemistry, Physics and New Directions X, Joint International Meeting of the 192nd Electrochemical Society, Le Palais Des Congres De Paris, Paris, France. Session on fullerene-based superconductors. Abstract deadline, March 3, 1997. Electronic submission of abstracts is encouraged and instructions are available at http://www.electrochem.org/abstracts.html. For information, contact The Electrochemical Society, Inc., 10 South Main Street, Pennington, NJ 08534-2896; telephone (609) 737-1902; telefax (609) 737-2743; e-mail ecs@electrochem.org; Web site http://www.electrochem.org.

Oct. 12 - 15, 1997: 49th Pacific Coast Regional Meeting and the Basic Science Division 1997 Fall meeting, Sheraton Palace Hotel, San Francisco, CA. Session 3: Ceramics of High Temperature Superconductors -- Ten Years of Intense Research. Debate persists about the pathways and mechanisms of achieving high critical currents, even while great progress has been made with phase diagrams, thermodynamics, etc. Call for papers. This symposium welcomes new data, review data, and debatable data. Abstracts may be submitted to the American Ceramic Society Headquarters by mail or electronically using the form available at the Web site http://www.acers.org/. For information, contact Peter D. Morgan, Session Chair, Rockwell Science Center, 1048 Camino Dos Rios, Thousand Oaks, CA 91360; telephone (805) 373-4273; telefax (805) 373- 4775; e-mail pemorgan@scimail.risc.rockwell.com.

*April 20 - 25, 1998: The Seventh Conference on Frontiers of Electron Microscopy in Materials Science, Kloster Irsee, Irsee, Germany. Purpose of this meeting is to establish the current state of the art of quantification of all relevant techniques used in electron microscopy including XEDS, EELS, Z-contrast, HREM, conventional TEM, CBED, and in- situ. Topical area: quantitative methods in electron microscopy. Number of participants limited to 100 (30 invited speakers, 20 invited session chairs, and 50 participants). For information, contact Kloster Irsee, Schwaebisches Tagungs- und Bildungszentrum, Klosterring 4, 87660 Irsee, Germany; telephone +49 8341 906-00; telefax +49 8341 742-78.

*Sept. 13 - 18, 1998: 1998 Applied Superconductivity Conference, Marriott's Desert Springs Resort, Palm Desert, CA. Major areas: superconducting materials for a wide range of applications, superconducting electronics, and large-scale applications. For information contact Centennial Conferences; telephone (303) 499-2299; telefax (303) 499-2599; e-mail centennial@orci.com.

RESOURCES

Information

Books: Macroscopic Quantum Phenomena and Coherence in Superconducting Networks, proceedings of Workshop held in Frascati, Italy, March 2 - 5, 1995, edited by C. Giovannella and M. Tinkham. Reviews progress in the physics of superconducting arrays. Consists of five sections: From the Single Superconducting Junction to the Josephson Junction Array -- An Introduction to Theory, Meaningful Experiments, and Technology; Charging Effects and Phase Transitions; Static Properties of Classical JJ Arrays; Dynamic and Coherence in Classical JJ Arrays; and Toward JJ Arrays Applications. Publ. 1995; 408 pp.; price $86; ISBN 981-02-2354-4.

Lecture Notes on Electron Correlation and Magnetism: Vol. 5 in Series on Modern Condensed Matter Physics, by P. Fazekas. Based on material presented at the Diploma Course of the International Centre for Theoretical Physics, Trieste, and at Budapest University. Attempts to fill the gap between standard introductory texts and the specialized literature describing recent developments. Discusses basic questions of the theory of magnetism, current interest in heavy fermions, Mott transition, quantum magnetism, and some recent experimental findings. Also contains problems and detailed solutions. No specialized training in advanced theoretical methods is assumed. Publ. 1996; 400 pp.; price $58; ISBN 981-02-2474-5.

Contact World Scientific Publishing Co. Inc., 1060 Main St., River Edge, NJ 07661; telephone (800) 227-7562 or (201) 487-9655; telefax (201) 487- 9656. In Europe, World Scientific Publishing Co. Ltd., 57 Shelton Street, Covent Garden, London WC2H 9HE, UK; telephone +44 171 836 0888; telefax +44 171 836 2020. In Asia, World Scientific Publishing Co. Pte. Ltd., Farrer Road, P.O. Box 128, Singapore 9128; telephone +65 3825663; telefax +65 3825919; telex RS 28561 WSPC; cable COSPUB. Information also available at the Web sites http://www.singnet.com.sg/~wspclib or http://www.wspc.co.uk.

New Book: SQUID Sensors: Fundamentals, Fabrication, and Applications, edited by Harold Weinstock. Book examines all aspects of constructing and using SQUID magnetic sensors that operate at either liquid-helium or liquid-nitrogen temperatures. Covers a range of established and emerging applications: biomagnetism, geophysics, nondestructive evaluation, detection of unexploded ordnance, and gravity gradiometry. Principles of both dc and rf SQUIDS discussed, as are geometries, electronic circuitry, and analysis techniques required to maximize performance. Publ. 1996; 720 pp.; price $349; ISBN 0-7923-4350-6.

In the U.S., contact Kluwer Academic Publishers, Order Department, P.O. Box 358, Accord Station, Hingham, MA 02018-0358; telephone (617) 871- 6600; telefax (617) 871-6528; e-mail kluwer@wkap.com. Elsewhere, contact Kluwer Academic Publishers, Book Department, P.O. Box 322, 3300 AH Dordrecht, The Netherlands; telephone +31 78 639 23 92; telefax +31 78 654 64 74; e-mail services@wkap.nl.

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

New Web site: The superconductivity group at the INFP Institut (Forschungszentrum Karlsruhe) have announced a new Web site featuring their latest developments in HTSC bulk materials, thin films, and applications such as superconducting bearings and flywheels. The URL is http://www.infp.fzk.de.

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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, #5, March 1, 1997.