Published for the Division of Materials Sciences, Office of Basic Energy Sciences, USDOE, under Contract W-7405-eng-82 with the Ames Laboratory, Iowa State University. Funded by DMS/BES/USDOE, ARPA, NSF, and other agencies, organizations, and individuals.
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: The following Nota Bene is contributed by David C. Johnston, Professor of Physics at Iowa State University and Senior Physicist at the Ames Laboratory. Our Science Editor, John R. Clem, is currently on travel.
Authors: Please remember to send us your papers prior to publication in a journal for listing in High-Tc Update. The newsletter lists only preprints and not reprints.
Stripes
The possible existence and influence of charge/spin stripes in superconducting cuprates is a topic of active research interest. E. S. Bozin (Michigan State) et al. have studied the local structure of La2- xSrxCuO4 (0 <= x <= 0.30) using atomic pair distribution function (PDF) analysis of neutron powder diffraction data. For x > 0, the results are consistent with the presence of local octahedral-tilt disorder in the form of a mixture of low-temperature-orthorhombic (LTO) and low- temperature-tetragonal (LTT) local tilt directions. The authors present topological tilt models which qualitatively explain the origin of tilt disorder in the presence of charge stripes and show that the PDF data are well explained by such a mixture of locally small and large amplitude tilts.
Pseudogap
The doping-dependent density of states in single crystals of La2- xSrxCuO4 (0.074 <= x <= 0.30) has been investigated using high- resolution angle-integrated photoemission spectroscopy measurements by A. Ino et al. (U. Tokyo). As x decreases, the spectral density of states at the chemical potential is suppressed with an x-dependence similar to the suppression of the electronic specific heat coefficient. In the underdoped region, the spectra show a pseudogap structure on the energy scale of 0.1 eV. The width of the pseudogap increases with decreasing x and follows the x-dependence of the characteristic temperatures of the uniform magnetic susceptibility and the Hall coefficient. The authors suggest that the origin of the large pseudogap is most likely due to antiferromagnetic correlations or short-range antiferromagnetic order.
Bi2212
The thermal conductivity kappa of Bi2Sr2CaCu2O8 crystals at temperatures down to 0.1 K was measured in magnetic fields H up to 18 kOe by H. Aubin (CNRS, Orsay) et al. Below 1 K, kappa increases with increasing H, whereas this and previous studies showed that above 5 K, kappa(H) exhibits a decrease followed by a plateau. The new behavior observed below 1 K is indicative of a finite density of states rather than the field-induced fully gapped state previously proposed to describe the plateau region at higher T. The authors infer that their low-T results are in agreement with theory predicting a field-induced enhancement of kappa arising from Doppler shift of quasiparticle excitations due to the finite local superfluid velocity.
123-Type Compounds
A detailed description of the fabrication of high-density BaZrO3 ceramic crucibles and their use in growing high-purity (99.99-99.995%) YBa2Cu3O7-d crystals with high crystal perfection is given in a preprint by R. Liang et al. (Vancouver). The crucibles have a long lifetime and can be reused for several crystal growth runs. The crystals, grown using a BaO-CuO self-flux method, show an extremely sharp x-ray rocking curve (FWHM = 0.007 degree), very weak magnetic flux pinning and a magnetic irreversibility line that lies about 20 K below the line for the best crystals grown using yttria-stabilized zirconia crucibles. An apparently smooth parabolic variation of Tc with delta is found for 6.86 <= (7-delta) <= 6.99. The maximum Tc of the crystals is 93.7 K at (7-delta) = 6.91 with a transition width of 0.2 K at an applied field of 3 Oe parallel to the c-axis. The Tc of an overdoped crystal with (7-delta) = 6.99 is about 88.5 K.
An infrared study of crystal-field excitations in NdBa2Cu3O6 is reported in a preprint by A. A. Martin (MPI, Stuttgart) et al. A more precise set of crystal-field parameters was obtained compared to previous results. Crystal-field transitions from Nd^[3+] ions on the Ba sites were also observed.
214-Type Compounds
The temperature dependence of the mid-infrared optical absorption of single crystal Sr2CuO2Cl2 is reported in a preprint by H. S. Choi (Seoul) et al. The measurements were carried out in transmission. The authors studied the temperature dependence of three peaks, a lower- energy sharp peak and two higher-energy broad peaks. With increasing temperature, the first peak (at ~ 3000 cm^[-1]) shows position red shift and width broadening and is attributed to phonon-assisted two-magnon excitations. In order to explain the anomalous broadening of the peak around the Neel temperature, the authors suggest a magnon scattering mechanism coupled with magnetic disorder in the CuO2 plane.
Measurements of the elastic energy absorption versus temperature in polycrystalline samples of La2CuO4+d are reported in a preprint by F. Cordero (Rome) et al. They find evidence that the excess O forms two different types of defects, even at very low concentrations, which are proposed to be monatomic and diatomic species. A. Hamed et al. (Houston) have carried out oxygen effusion measurements on polycrystalline samples with 0 < delta < 0.12 from 300 to 900 K. Analysis of the data indicates that the rate limiting step for oxygen evolution is surface desorption rather than a bulk process, with the order of the reaction being close to 2.
The low-temperature (0.2 K to 4 K) specific heat C(T) of three samples of the electron-doped system Pr2-xCexCuO4-d is reported in a preprint by T. E. Hargreaves (U. Sussex) et al. Irrespective of whether a sample is superconducting or not, the zero-field C(T) consists of a nuclear term, a phononic term and a residual T^n term where n < 1. The last term follows an unusual temperature dependence in a magnetic field. The authors suggest that this term arises from disorder-induced localization of normal carriers at low temperatures.
Vortices
Vortex pinning was studied by J. A. Herbsommer (Bariloche) et al. in single crystals of YBa2Cu3O7-d with columnar defects which have splay angles of 0 degree, 10 degrees and 20 degrees with respect to the c- axis. An increase of pinning when the field direction is inside the angle defined by the columnar defects was attributed to vortex entanglement due to the splay and the suppression of the sliding of double kinks.
Theory
The superconducting pair-pair correlation function of the two- dimensional t-J model is studied by C. T. Shih (Hsinchu) et al. using the power-Lanczos method. The authors conclude that this model does not have long-range d-wave superconducting correlations in the physically relevant parameter range J/t <= 0.5.
In a related preprint, H.-B. Schuettler (U. Georgia) et al. study strongly correlated Hubbard quasi two-dimensional (2D) electron systems near half-filling. They find that doping-induced charge fluctuations cause overscreening of the electron-electron Coulomb repulsion. The resulting attractive screened interaction potential is found to support d_[x^2-y^2] pairing with a doping-dependent pairing strength at lower doping, followed by s-wave pairing at higher doping. G. Esirgen (U. Georgia) et al. find that including the long-range (1/r) part of the Coulomb interaction up to 4th neighbor distance in the one-band extended Hubbard model in 2D near half-filling still yields d_[x^2-y^2] pairing when the first neighbor repulsion strength V_1 is moderate. At large V_1 ~ U, incipient charge density wave instabilities tend to suppress this pairing state.
The repulsive Hubbard model on a square lattice with an additional term which depends on the square of the single-particle nearest-neighbor hopping is studied using large scale (24 x 24) quantum Monte-Carlo simulations by F. F. Assaad (U. Stuttgart). Enhancing U/t is found to drive the system from a d-wave superconductor to an antiferromagnetic Mott insulator. The results show the compatibility and close interplay of antiferromagnetic fluctuations and d-wave superconductivity.
The interaction of long-range antiferromagnetism and superconductivity is analyzed within a generalized Hubbard model with nearest-neighbor correlated hopping in a square lattice by L. Arrachea (MPI Dresden, Freien U. Berlin) and A. A. Aligia (Bariloche). They find that due to the contribution of triplet pairs with d-wave symmetry and total momentum (pi,pi), the coexistence of superconductivity and long-range antiferromagnetism is ruled out for large values of U. Spin-density wave fluctuations do not change this result.
The in-plane magnetoresistance of YBa2Cu3O7 in a magnetic field perpendicular to the CuO2 layers is calculated by A. T. Zheleznyak et al. (U. Maryland) for the "cold spots" model with two distinct relaxation times on different parts of the Fermi surface. The results predict a strong violation of Kohler's rule, in agreement with experiment.
Films, Applications
In-plane- (c-axis-) aligned superconducting (Tl,Bi)-1223 films were grown on rolling-assisted-biaxially-textured substrates by Z. F. Ren (S.U.N.Y., Buffalo) et al., via laser ablation of a precursor film followed by post-ablation annealing. Tl0.78Bi0.22Sr1.6Ba0.4Ca2Cu3O9 films with Tc = 105-109 K (from resistivity measurements) were obtained with a critical current density of 4.25 x 10^5 A/cm^2 at 77 K and zero- field. For magnetic fields along the c-axis, the irreversibility field was above 3 T at 77 K and above 5 T at 64 K.
Pure and Re-doped c-axis HgBa2Ca2Cu3Oy (Hg-1223) superconducting thin films were fabricated on SrTiO3 (100) substrates by pulsed laser deposition followed by annealing in mercury-vapor atmosphere by Y. Moriwaki (ISTEC) et al. The Re-doped films exhibit a zero-resistance Tc up to 127.5 K, a transport critical current density at 77 K of Jc = 1.5 x 10^6 A/cm^2 in the self-field and 1.2 x 10^5 A/cm^2 under a magnetic field of 1 T parallel to the c-axis. The irreversibility field above 77 K of the Re-doped films is substantially higher than those for undoped Hg-1212 and Tl-1223 thin films.
Using a pre-annealing and intermediate-rolling-and-melt-solidification process, H. Miao (NRIM, Tsukuba) et al. obtained Bi-2212/Ag multilayer tapes with Jc > 5 x 10^5 A/cm^2 at 4.2 K and 10 T. The authors state that their processing methods are applicable for fabricating long Bi- 2212 tapes with large transport Jc for practical applications.
Ba2GdNbO6 was developed as a new substrate material suitable for use with the Bi-based cuprate superconductors by J. Kurian et al. (Trivandrum). Dip-coated films of Bi-2223 showed Tc = 109 K and Jc ~~ 4 x 10^3 A/cm^2 at 77 K in zero applied field.
Bicrystal YBa2Cu3O7-d Josephson junctions were fabricated by C. Weber (Juelich) et al. Under microwave radiation, the junctions exhibited first current (Shapiro) steps with an amplitude of 1 mA at 80 K, made possible because of the large critical current of the junctions. The authors discuss deviations of the observed behaviors from the resistively-shunted-junction model, and discuss the impact on metrological applications (e.g., voltage standards) of high-temperature superconductor Josephson junctions.
As reported by Y. Kumagai (Nagoya) et al., Nd1+xBa2-xCu3O7-y superconducting thin films were fabricated using metal-organic chemical vapor deposition using non-fluorinated sources. The films deposited at an oxygen pressure of 0.01 Torr were high-quality c-axis-oriented films with the stoichiometric composition. These films were superconducting with Tc ~~ 50 K by both electric and magnetic measurements.
In-plane aligned YbBa2Cu3O7-d films were prepared by the chemical solution deposition method by K. Yamagiwa and I. Hirabayashi (ISTEC). The zero-resistance Tcs of films on SrTiO3 (100) were above 89 K with a typical Jc of about 10^5 A/cm^2 at 77 K and 0 T.
The character and acquisition of multichannel biomagnetic data are studied by J. Vrba and J. McKay (CTF Systems). The authors show that the presence of environmental noise and the requirements for noise cancellation dictate certain specifications for the system dynamic range, slew rate, linearity and inter-channel matching. It was found that magnetometer-based systems are subject to far more stringent requirements than gradiometer-based systems.
Reviews
Numerical and analytical results which support SO(5) symmetry as a concept unifying superconductivity and antiferromagnetism in the high- temperature superconductors are reviewed by W. Hank et al. (Wuerzburg). Experimental tests and consequences such as the relationship between the photoemission spectra of the insulator and superconductor are emphasized. (39 refs.).
A short review of recent progress in the synthesis of thin-film 214-type superconductors by molecular beam epitaxy (MBE) is given by M. Naito et al. (NTT, Kanagawa), where the strong influences of the oxygen stoichiometry and defect structure are emphasized. They obtain high- quality La2CuO4+d films with Tc ~~ 50 K, and (Nd,Ce)2CuO4 films with sharp transitions at Tc ~~ 24 K. They also review their recent discovery of superconductivity in Ba2CuO4-d films with the K2NiF4 structure, which exhibit a Tc onset near 90 K from magnetic susceptibility measurements. (23 refs.).
Ph.D. Thesis
Ion-beam-assisted pulsed-laser deposition of biaxially oriented oxide buffer layers on non-textured substrates is studied in the thesis of V. Betz (Dresden). Buffer layers included yttria, yttria-stabilized zirconia (YSZ), Pr6O11, Gd2O3 and CeO2. The microstructure of the buffer layers was examined using TEM and AFM in conjunction with x-ray texture analysis. Superconducting YBa2Cu3O7-d (YBCO) films were epitaxially deposited using pulsed-laser deposition on a thin CeO2 layer coating a biaxially textured YSZ buffer layer on non-textured metal substrates. The oriented YBCO films show a critical current density of over 1 x 10^6 A/cm^2, which is about 40% of the value for YBCO films on single-crystal substrates. (150 refs.).
Contributed by David C. Johnston
Contents: Technology News is on page 4; Preprints begin on page 4; and Coming Events begin on page 10.
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.
A collaboration between Cryogenic Ltd. and American Superconductor Corporation seeks to extend the range of compact superconducting magnets to 22 T. Cryogenic had commenced tests on an insert coil which will form part of the first 22 T superconducting magnet to be built by the firm; the aim is to provide 22 T in a 30 mm working space within a practical design that is compact and convenient to use. The general design of the magnet follows the conventional approach of using a NbTi conductor to provide a backing field of some 11 T (at 2.2 K), and then utilizing the higher current densities available from advanced Nb3Sn conductor to generate a combined central field in excess of 20 T. The final 2 T central field is then realized from a HTS superconducting coil insert which offers the high current densities at liquid-helium temperatures. The complete magnet is expected to generate 22 T in a central 30 mm bore. For further information, contact Cryogenic Limited, Unit 30, Action Park Industrial Estate, The Vale, London W3 7QE, United Kingdom; telephone +44 181 743 6069; telefax +44 181 749 5315; Web site http://www.cryogenic.co.uk.
A subcontract has been awarded to Conductus, Inc., by Communication Solutions Inc. (CSI) of Baltimore, for the fabrication of a superconductor-enhanced multichannel wireless receiver front end. CSI will then integrate this into a high-performance system earmarked for a number of government communications applications. For further information, contact Randy Simon, Vice President for Technology Programs, Conductus, Inc., 969 West Maude Ave., Sunnyvale, CA 94086; telephone (408) 523-9473; telefax (408) 523-9999.
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. Aburto, L. Fruchter, and C. Pasquier, "Penetration Depth, Superconducting Transition Temperature and Quenching of kappa-(BEDT- TTF)2Cu[N(CN)2]Br." To be published in Physica C (in press). Laboratoire de Physique des Solides, Universite Paris-Sud C.N.R.S., F- 91405 Orsay Cedex, FRANCE; telephone +33 1 69 15 60 89; telefax +33 1 69 15 56 54; e-mail fruchter@lps.u-psud.fr. Key words: organic superconductor, penetration depth, structural phase transition. 74.62.Dh; 74.70.Kn; 74.60.Ec.
S. K. Agarwal, A. Iyo, K. Tokiwa, Y. Tanaka, K. Tanaka, M. Tokumoto, N. Terada, T. Saya, M. Umeda, H. Ihara, M. Hamao, T. Watanabe, and A. V. Narlikar, "Superconductivity in Mg Doped CuBa2Ca3Cu4O12-y System." To be published in Phys. Rev. B. Contact H. Ihara, Electrotechnical Laboratories, 1-1-4 Umezono, Tsukuba, Ibaraki 305-8568, JAPAN; e-mail h.ihara@etl.go.jp.
Liliana Arrachea and A. A. Aligia, "Does Long-Range Antiferromagnetism Help or Inhibit Superconductivity?" To be published in Physica C (in press). Contact A. A. Aligia, Centro Atomico Bariloche and Instituto Balseiro, Comision Nacional de Energia Atomica, 8400 Bariloche, ARGENTINA; telephone +54 944 45170; telefax +54 944 45299; e-mail aligia@cab.cnea.edu.ar. Key words: generalized Hubbard model, three- body interactions, d-wave superconductor, phase diagram, Hartree-Fock- BCS approximation.
F. F. Assaad, "The Interplay Between d-Wave Superconductivity and Antiferromagnetic Fluctuations: A Quantum Monte Carlo Study." Institut fuer Theoretische Physik III, Universitaet Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, GERMANY; telephone +49 711 685 5212; telefax +49 711 685 5098; e-mail assaad@theo3.physik.uni-stuttgart.de; preprint also available at cond-mat@xxx.lanl.gov (#9806306).
Herve Aubin, Kamran Behnia, Shuuichi Ooi, and Tsuyoshi Tamegai, "Evidence for Field-Induced Excitations in Low-Temperature Thermal Conductivity of Bi2Sr2CaCu2O8." Submitted to Phys. Rev. Lett. Contact Kamran Behnia, Laboratoire de Physique des Solides, Universite Paris- Sud, Batiment 510, F-91405 Orsay Cedex, FRANCE; e-mail kamran@lps.u- psud.fr; preprint also available at cond-mat@xxx.lanl.gov (#9807037). 74.25.Fy; 74.72.Bk; 72.15.Eb.
A. M. Balagurov, A. I. Beskrovny, V. Yu. Pomjakushin, V. G. Simkin, B. Sh. Bagautdinov, V. Sh. Shekhtman, and A. A. Zakharov, "Twinned Structure of La2CuO4 Crystals." Preprint #P14-98-9; submitted to Crystallography. Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, RUSSIA. (Preprint in Russian.)
Volker Betz, "Biaxially Oriented Film Growth Under Ion-Beam Assistance: High Critical Current Carrying Superconducting YBCO-Films on Non- Textured Substrates." Submitted as a Ph.D. thesis (Technical University Dresden). Institute fuer Metallische Werkstoffe, Institut fuer Festkoerper- und Werkstofforschung Dresden, P.O. Box 27 00 16, Helmholtzstr. 20, D-01069 Dresden, GERMANY; telephone +49 351 4659 206; telefax +49 351 4659 541; e-mail betz@ifw-dresden.de; Web site http://www.shaker.de/online-gesamtkatalog/details.idc?isbn=3-8265-3668- 1. (Thesis in German, abstract in English.)
E. S. Bozin, S.J.L. Billinge, G. H. Kwei, and H. Takagi, "Charge-Stripe Ordering from Local Octahedral Tilts: Underdoped and Superconducting La2-xSrxCuO4 (0 <= x <= 0.30)." Department of Physics and Astronomy and Center for Fundamental Materials Research, Michigan State University, East Lansing, MI 48824-1116; e-mail bozin@pa.msu.edu; preprint also available at cond-mat@xxx.lanl.gov (#9807151). 71.30.+h; 71.38.+i; 61.12.-q; 72.80.Ga.
L. X. Cao, B. R. Zhao, Y. L. Qin, L. Li, T. Yang, and Z. X. Zhao, "Electric Field Effect of YBa2Cu3O7 Film Modulated by Pb(Zr0.53Ti0.47)O3 Gate Layer." To be published in Physica C (in press). Institute for Materials Research, Tohoku University, Katahira 2-1-1, Sendai 980-8577, JAPAN; telephone +81 22 215 2024; telefax +81 22 215 2020; e-mail cao@fistm.imr.tohoku.ac.jp. Key words: multilayers, electrical resistivity, hole concentration, application of high-Tc superconductors, penetration depth.
C. M. Carlson, J. C. Price, P. A. Parilla, D. S. Ginley, D. Niles, R. D. Blaugher, A. Goyal, M. Paranthaman, D. M. Kroeger, and D. K. Christen, "Laser-Ablated Epitaxial LaAlO3 Buffer Layers on Biaxially-Textured Ni Substrates for Superconducting Tapes." To be published in Physica C (in press). Department of Physics, University of Colorado, Boulder, CO 80309-0390. Key words: LaAlO3, buffer layers, biaxial texture, rolled- Ni substrates, pulsed-laser deposition.
T. G. Chen, S. Li, W. Gao, H. K. Liu, and S. X. Dou, "The Oxygenation Processes of YBa2Cu3O6+d with Silver Additions." To be published in Physica C (in press). Contact W. Gao, Department of Chemical and Materials Engineering, University of Auckland, Auckland, NEW ZEALAND. Key words: oxygenation process, silver, YBa2Cu3O6+d.
H. S. Choi, E. J. Choi, and Y. J. Kim, "Temperature Dependence of the Mid-Infrared Absorptions in Undoped Cuprate Sr2CuO2Cl2." To be published in Physica C (in press). Department of Physics, Seoul National University, Seoul 151-742, SOUTH KOREA. Key words: Sr2CuO2Cl2, phonon-assisted bimagnon model, antiferromagnetic order, infrared spectroscopy.
F. Cordero, C. R. Grandini, and R. Cantelli, "Structure, Mobility and Clustering of Interstitial O in La2CuO4+d in the Limit of Small delta." To be published in Physica C. Istituto di Acustica "O.M. Corbino", CNR, Area di Ricerca di Roma-Tor Vergata, Via del Fosso del Cavaliere 100, I- 00133 Rome, ITALY; telephone +39 6 4993 4114; telefax +39 6 2066 0061; e-mail cordero@idac.rm.cnr.it. Key words: La2CuO4+d, interstitial O, O mobility, doping efficiency, anelastic spectroscopy.
C. M. da Silva, D. E. Brandao, and A. A. Gomes, "Pseudo-Quaternary Borocarbides: A Two Sublattice Model." To be published in Physica C (in press). Departamento de Fisica-UFSM, 97119-900 Santa Maria, RS, BRAZIL. Key words: pseudo-quaternary, borocarbides, sublattice model. 74.70.Ad; 75.90.+w.
I. Eremin, M. Eremin, and S. Varlamov, "Two Reasons of Instability in Layered Cuprates." To be published in J. Supercond.: Proc. of the Int. Conf. on Stripes, Lattice Instabilities, and High Tc Supercond., Rome, Italy, June 2-7, 1998. Department of Theoretical Physics, Kazan State University, 420008 Kazan, RUSSIA; e-mail ilya.eremin@ksu.ru. Key words: spin susceptibility, charge density wave, pseudogap.
Goekhan Esirgen, H.-B. Schuettler, and N. E. Bickers, "d-Wave Pairing in the Presence of Long-Range Coulomb Interactions." Center for Simulational Physics, Department of Physics and Astronomy, University of Georgia, Athens, GA 30602-2451; e-mail esirgen@uga.edu; preprint also available at cond-mat@xxx.lanl.gov (#9806264). 71.10.+x; 71.20.Ad.
E. J. Ferrer and V. de la Incera, "Magnetic Response in Anyon Fluid at High Temperature." Preprint #SUNY-FRE-98-06; presented at SILAFAE'98, San Juan, Puerto Rico, April 8-11, 1998. Department of Physics, State University of New York, Fredonia, NY 14063; e-mail ferrer@fredonia.edu; preprint also available at cond-mat@xxx.lanl.gov (#9807024).
E. J. Ferrer and V. de la Incera, "Phase Transition in Anyon Superconductivity at Finite Temperature." Preprint #SUNY-FRE-98-04. Department of Physics, State University of New York, Fredonia, NY 14063; e-mail ferrer@fredonia.edu; preprint also available at cond- mat@xxx.lanl.gov (#9805039).
Herman J. Fink, "Residual and Intrinsic Surface Resistance of YBa2Cu3O7- d." Submitted to Phys. Rev. B. Department of Electrical and Computer Engineering, University of California, Davis, CA 95616. 74.25.Nf; 74.20.De; 74.72.Bk; 74.25.Fy.
Philip A. Fisher, Joel N. Ullom, and Michael Nahum, "Development of a 100 mK Electronic Refrigerator Based on a Normal-Insulator- Superconductor Tunnel Junction." To be published in Appl. Supercond. (in press). Department of Physics, Harvard University, Cambridge, MA 02138.
W. T. Fu and R. J. Drost, "Superconductivity in the BaPb1-xBix/2Sbx/2O3 System." To be published in Physica C (in press). Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 Leiden, THE NETHERLANDS; telephone +31 71 527 4215; telefax +31 71 527 4537; e-mail fu_w@chem.leidenuniv.nl. Key words: synthesis, metal- insulator transition, ac susceptibility, electrical resistivity.
S. K. Gupta, D. K. Aswal, J. C. Vyas, and V. C. Sahni, "A Theoretical Analysis of the Resistance Changes Accompanying Oxygen Diffusion in YBa2Cu3Ox." To be published in Physica C (in press). Technical Physics and Prototype Engineering Division, Bhabha Atomic Research Center, Mumbai 400 085, INDIA; telefax +91 22 556-0750 or -0534. Key words: electrical resistivity, diffusion, high Tc, YBa2Cu3Ox. 66.30.-h.
A. Hamed, Z. G. Li, and P. H. Hor, "Kinetics of Oxygen Evolution in La2CuO4+d." Preprint #98:059; submitted to the Proc. of the 9th World Ceramic Congress and Forum on New Mater. (CIMTEC'98), Florence, Italy, June 14-19, 1998. 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.
Damian P. Hampshire, "Ferromagnetic and Antiferromagnetic Superconductivity." To be published in Physica C (in press). Superconductivity Group, Department of Physics, Durham University, Durham DH1 3LE, UNITED KINGDOM; telephone +44 191 374 2167; telefax +44 191 374 3749. Key words: ferromagnetic superconductivity, antiferromagnetic superconductivity, Gibbs free energy.
W. Hanke, R. Eder, E. Arrigoni, A. Dorneich, S. Meixner, and M. G. Zacher, "SO(5) Symmetry in t-J and Hubbard Models." Report #TP1-98-07; to be published in Adv. Solid State Phys. Institut fuer Theoretische Physik, Universitaet Wuerzburg, Am Hubland, D-97074 Wuerzburg, GERMANY; A. Dorneich's e-mail ardornei@physik.uni-wuerzburg.de; preprint also available at cond-mat@xxx.lanl.gov (#9807015).
T. E. Hargreaves, H. Noma, J. Akimitsu, D. F. Brewer, N. E. Hussey, and A. L. Thomson, "Low-Temperature Specific Heat of the Electron-Doped Superconductor Pr2-xCexCuO4-d." To be published in Physica C (in press). Contact D. F. Brewer, Pevensey 2 Building, University of Sussex, Brighton BN1 9QH, Sussex, UNITED KINGDOM. Key words: low- temperature specific heat, electron-doped cuprates, localization effects. 65.40.-f; 74.25.Bt; 74.72.Jt.
Kenji Hatada and Hajime Shimizu, "Structural and Superconducting Properties of R1-xCaxBa2Cu3O6+d (R=Y,Er,Gd,Eu; 0 < delta < 1)." To be published in Physica C (in press). Department of Electronics and Computer Science, Science University of Tokyo in Yamaguchi, Onoda, Yamaguchi 756, JAPAN; telephone +81 836 88 3500; telefax +81 836 88 3844; e-mail hatada@ed.yama.sut.jp. Key words: Ca-doped YBCO, substitutional effect, Tc-plateau.
J. A. Herbsommer, J. Luzuriaga, L. Civale, G. Nieva, G. Pasquini, H. Lanza, and P. Levy, "Angular Variation of Pinning Near the Irreversibility Temperature in Single Crystal YBa2Cu3O7-d with Splayed Columnar Defects." To be published in Physica C (in press). Centro Atomico Bariloche and Instituto Balseiro, Comision Nacional de Energia Atomica (CNEA) and UNC, 8400 S. C. de Bariloche, ARGENTINA. Key words: flux pinning, pinning force, critical current density, columnar defects.
A. Ino, T. Mizokawa, K. Kobayashi, A. Fujimori, T. Sasagawa, T. Kimura, K. Kishio, K. Tamasaku, H. Eisaki, and S. Uchida, "Doping Dependent Density of States and Pseudogap Behavior in La2-xSrxCuO4." Submitted to Phys. Rev. Lett. Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, JAPAN; telephone +88 3 5800 3325; telefax +88 3 5800 3325; e-mail ino@wyvern.phys.s.u-tokyo.ac.jp; preprint also available at cond-mat@xxx.lanl.gov (#9806363). 71.30.+h; 74.72.Dn; 74.25.Jb; 79.60.Bm.
Takanori Itoh, Kazuo Fueki, Yasumoto Tanaka, and Hideo Ihara, "Optical Conductivity Spectra and Electronic Structure of Bi2Sr2(Y1-xCax)Cu2Oy System." To be published in J. Phys. Chem. Solids. Department of Industrial Chemistry, Faculty of Science and Technology, Science University of Tokyo, 2641 Yamazaki, Noda-shi, Chiba 278, JAPAN; e-mail a7292701@mail.rs.noda.sut.ac.jp or Yasumoto Tanaka's e-mail y.tanaka@etl.go.jp. Key words: superconductors, thin film, infrared spectroscopy, electrical properties.
Young A. Jee, Gye-Won Hong, Tae-Hyun Sung, and Chan-Joong Kim, "Control of the Growth Rate of YBa2Cu3Ox Single-Domained Crystal by Applying Two Step Undercooling in Top-Seeded Melt Growth." To be published in Physica C. Superconductivity Research Laboratory, Korea Atomic Energy Research Institute, P.O. Box 105, Yusong, Taejon 305-600, SOUTH KOREA; telephone +82 42 868 8029; telefax +82 42 862 5496; e-mail icicle@nanum.kaeri.re.kr. Key words: YBa2Cu3Ox, single crystal, melt processing, top-seeded melt growth (TSMG), two-step undercooling.
K. Kanehashi, M. Kikuchi, H. Tokuno, and Y. Syono, "Superconductivity and Valence Analysis of Pb and Cu of the (Pb,Cd)-12(n - 1)n (n = 1,2) Cuprate Superconductors." To be published in Physica C (in press). Contact M. Kikuchi, Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980, JAPAN; telephone +81 22 215 2087. Key words: superconductivity, valence analysis, Pb, Cu, cuprate superconductors.
Gwang-Hee Kim and Mincheol Shin, "Quantum Vortex Creep: Hall and Dissipative Tunneling." To be published in Physica C (in press). Department of Physics, Sejong University, Seoul 143-747, SOUTH KOREA; e- mail gkim@kunja.sejong.ac.kr. Key words: vortex, tunneling, creep, Hall, dissipation. 74.60.Ge.
M. Kiviranta and H. Seppae, "Noise Simulation of the un SQUID." To be published in Appl. Supercond. (in press). VTT Automation, Measurement Technology, P.O. Box 1304, 02044 VTT, FINLAND; telefax +358 456 7029; Web site http://www.vtt.fi/aut/mit/st.
Z. Klencsar, E. Kuzmann, Z. Homonnay, A. Vertes, K. Vad, J. Bankuti, T. Racz, M. Bodog, and I. Kotsis, "The Effect of Pr Substituted in Eu1- xPrxBa2Cu3O7-d and EuBa2-xPrxCu3O7-d Perovskites." To be published in Physica C (in press). Department of Nuclear Chemistry, Eoetvoes University, Budapest, HUNGARY; telephone +36 1 209 0555; telefax +36 1 209 0602; e-mail susu77@ludens.elte.hu. Key words: Mossbauer, praseodymium, substitution, critical temperature, HTSC. 74.72.-h; 74.72.Bk; 74.62.Dh.
Yoshifumi Kumagai, Yutaka Yoshida, Morihiro Iwata, Masato Hasegaw, Yoshihiro Sugawara, Tukasa Hirayama, Izumi Hirabayashi, and Yoshiaki Takai, "Fabrication and Characterization of Nd1+xBa2-xCu3O7-y Thin Films Deposited by Metal-Organic Chemical Vapor Deposition Using Liquid State Sources." To be published in Physica C (in press). Department of Energy Engineering and Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, JAPAN. Key words: MOCVD, NdBa2Cu3O7-y, thin film, c- axis length, liquid source, Nd-Ba substitution, TEM-EDX.
Martin Kupka, "The Effect of the Superconductive-Electrode Transition Surface Region on the Contact Differential Conductance." To be published in Physica C (in press). Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04353 Kosice, SLOVAK REPUBLIC; telephone +421 95 633 6292; telefax +421 95 622 8158; e-mail kupkam@linux1.saske.sk. Key words: tunneling, superconducting microconstriction, N-S'-S structures.
J. Kurian, K.V.O. Nair, P. K. Sajith, Asha M. John, and J. Koshy, "Bi(2223) Thick Films (Tc(0) = 109K) on Ba2GdNbO6: A New Perovskite Ceramic Substrate for BSCCO Superconductor." To be published in Appl. Supercond. (in press). Contact J. Koshy, Regional Research Laboratory (CSIR), Trivandrum 695 019, INDIA.
K. Lebbou, S. Trosset, R. Abraham, M. Th. Cohen-Adad, M. Ciszek, and W. Y. Liang, "Thallium Cuprate 1223 Type: I. Its Elaboration and Dependence of Chemical and Thermal Stability and of Superconducting Transition Temperature on Tl/Pb and Sr/Ba Substitutions." To be published in Physica C (in press). Laboratoire de Physicochimie Minerale II, Universite Claude Bernard Lyon 1, F-69622 Villeurbanne Cedex, FRANCE; telephone +33 4 7244 8130; telefax +33 4 7243 1233; e- mail lebbou@cismsun.univ-lyon1.fr. Key words: Tl, Pb-Sr, Ba-1223, superconductors, synthesis, equibrium phase diagram, monophased field.
J. Q. Li, C. C. Lam, K. C. Hung, and L. J. Shen, "Enhancement of Critical Current Density in HgBa2Ca2Cu3O8+d Superconductor Doped by Sb." To be published in Physica C (in press). Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, PEOPLE'S REPUBLIC OF CHINA; telephone +852 2788 7831; telefax +852 2788 7830; e-mail apcclam@cityu.edu.hk. Key words: critical current density, superconductors, doping.
Ruixing Liang, D. A. Bonn, and W. N. Hardy, "Growth of High Quality YBCO Single Crystals Using BaZrO3 Crucibles." To be published in Physica C (in press). Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC, CANADA V6T 1Z1. Key words: YBa2Cu3O7-x cuprate, YBCO, single-crystal growth, BaZrO3 crucible, x-ray diffraction, magnetization. 74.72.Bk; 81.10.Fq; 61.72.- y; 81.05.Je.
H. B. Liu, Paulo J. Ferreira, and John B. Vander Sande, "Processing Bi- 2212/Ag Thick Films Under a High Magnetic Field: On the Bi-2212/Ag Interface Effect." To be published in Physica C (in press). Contact Paulo J. Ferreira, Department of Materials Science and Engineering, Massachusetts Institute of Technology, Room 13-5134, Cambridge, MA 02139; telephone (617) 253-6923; telefax (617) 268-7874. Key words: Bi-2212, Ag, magnetic field.
T. Manabe, Y. Yajima, I. Yamaguchi, T. Kumagai, T. Shimizu, and S. Mizuta, "Solid-State Epitaxy of c-Axis-Oriented Yb124 Films Prepared by Coating-Pyrolysis Process." To be published in Physica C (in press). National Institute of Materials and Chemical Research, Tsukuba, Higashi 1-1, Ibaraki 305-8565, JAPAN; telephone +81 298 54-4556; telefax +81 298 54-4709 or -4408; e-mail manabe@ccmail.nimc.go.jp. Key words: YbBa2Cu4O8, synthesis, thin films, epitaxy, substitution effects.
C. Manfredotti, M. Truccato, P. Volpe, P. Benzi, N. Rizzi, S. Sanguinetti, and D. Allasia, "Crystal Growth Dependence on the Starting Chemical Compounds in the Bi2Sr2Ca2Cu3Ox System." To be published in Physica C (in press). Contact M. Truccato, Dipartimento di Fisica Sperimentale, INFM-UdR Torino Universita, Via P. Giuria 1, I-10125 Torino, ITALY; telephone +39 11 670 7326; telefax +39 11 669 1104; e- mail truccato@to.infn.it. Key words: synthesis of Bi2Sr2Ca2Cu3O10, granular superconductivity, ac susceptibility, electrical resistivity. 81.20.Ev; 81.40.Rs.
Chuanbin Mao, Lian Zhou, Xiaozu Wu, and Xiangyun Sun, "Rapid One-Powder Process to Synthesize Phase Assemblage Composed of (Bi,Pb)2Sr2CaCu2Ox, Ca2CuO3 and CuO." To be published in Physica C (in press). Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, PEOPLE'S REPUBLIC OF CHINA; telephone +86 10 6278-2966 or -2346; telefax +86 10 6277 0302. Key words: BiPbSrCaCuO powder, (Bi,Pb)2Sr2Ca2Cu3Ox, one-powder process. 74.72.Hs; 81.20.Ka.
A. A. Martin, T. Ruf, M. Cardona, S. Jandl, D. Barba, V. Nekvasil, M. Divis, and T. Wolf, "Infrared Study of Crystal-Field Excitations in NdBa2Cu3O6." Submitted to Phys. Rev. B. Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, GERMANY; telephone +49 711 689 1754; telefax +49 711 689 1712; e-mail amartin@cardix.mpi-stuttgart.mpg.de. 78.30.Hv; 71.70.-d; 63.20.Ls.
H. Miao, H. Kitaguchi, H. Kumakura, K. Togano, T. Hasegawa, and T. Koizumi, "Bi2Sr2CaCu2Ox/Ag Multilayer Tapes with Jc (4.2K, 10T) > 500,000 A/cm^2 by Using Pre-Annealing and Intermediate Rolling Process." To be published in Physica C (in press). Contact H. Kitaguchi, National Research Institute for Metals, 1-2-1 Sengen, Tsukuba, 305-0047, JAPAN; telephone +81 298 59 2329; telefax +81 298 59 2301; e-mail hk@nrim.go.jp. Key words: Bi-2212, tape, PAIR process, critical current density, post annealing. 74.72.Hs; 85.25.Kx.
Y. Moriwaki, T. Sugano, A. Tsukamoto, C. Gasser, K. Nakanishi, S. Adachi, and K. Tanabe, "Fabrication and Properties of c-Axis Hg-1223 Superconducting Thin Films." To be published in Physica C (in press). Superconductivity Research Laboratory, International Superconductivity Technology Center (ISTEC), 10-13 Shinonome 1-chome, Koto-ku, Tokyo 135, JAPAN; telephone +81 3 3536-5703 through -5705; telefax +81 3 3536-5714 or -5717. Key words: Hg-1223 thin film, Re doped, pulsed-laser deposition, high-Jc.
Mi-Ock Mun, Mun-Seog Kim, Sung-Ik Lee, B. K. Cho, In-Sang Yang, W. C. Lee, and P. C. Canfield, "Determination of the Precise Upper Critical Field of YNi2B2C Superconductor." To be published in Physica C (in press). Department of Physics, Pohang University of Science and Technology, Pohang 790-784, SOUTH KOREA. Key words: upper critical field, YNi2B2C superconductor, paramagnetic susceptibility, Curie-Weiss behavior.
M. Muralidhar, H. S. Chauhan, and M. Murakami, "Effect of Y and Gd Additions on the Jc-B Properties of (Nd,Sm,Eu)123 System." Superconductivity Research Laboratory, International Superconductivity Technology Center (ISTEC), 3-35-2 Iioka-Shinden, Morioka, Iwate 020- 0852, JAPAN; telephone +81 19 635-9015 or -9016; telefax +81 19 635- 9017; e-mail miryala@istec.or.jp. Key words: melt process, (Nd,Sm,Eu)123, flux pinning, peak effect, critical current density.
M. Muralidhar, T. Saitoh, K. Segawa, and M. Murakami, "Superconducting Properties of (Nd,Sm,Eu,Gd)-Ba-Cu-O." To be published in Appl. Supercond. Superconductivity Research Laboratory, International Superconductivity Technology Center (ISTEC), 3-35-2 Iioka-Shinden, Morioka, Iwate 020-0852, JAPAN; telephone +81 19 635-9015 or -9016; telefax +81 19 635-9017; e-mail miryala@istec.or.jp. Key words: melt process, oxygen partial pressure, (Nd,Sm,Eu,Gd)-Ba-Cu-O, critical temperature, critical current density.
T. Nagaishi, H. Toyoda, H. Kugai, and H. Itozaki, "Detection of Moving Fine Iron Particles by High-Tc SQUID." To be published in Applied Supercond. (in press). Itami Research Laboratories, Sumitomo Electric Industries, 1-1 Koya-kita, 1-chome, Itami 664, JAPAN.
T. Nagano, S. Inoue, T. Hashimoto, and J. Yoshida, "Interface Fabrication of YBa2Cu3Oy Ramp-Edge Junction with PrBa2(Cu1-xCox)3Oy Barrier Layer in Enhanced Oxidizing Atmosphere." To be published in Physica C (in press). Advanced Research Laboratory, Toshiba 1, Komukai Toshiba-cho, Saiwai-ku, Kawasaki 210, JAPAN. Key words: ramp-edge junction, YBa2Cu3Oy, electron cyclotron resonance.
Michio Naito, Hisashi Sato, and Hideki Yamamoto, "Oxygen Nonstoichiometry of MBE-Grown Cuprate Films to Lose or Give High-Tc Superconductivity." To be published in the Proc. of SPIE's 43rd Annual Meeting on Optical Science, Engineering, and Instrumentation, San Diego, Calif., July 19-24, 1998. NTT Basic Research Laboratories, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-01, JAPAN; telephone +81 462 40 3516; telefax +81 462 70 2364; e-mail michio@will.br1.ntt.co.jp. Key words: high-Tc superconductors, oxygen nonstoichiometry, surface/interface analysis, (Nd,Ce)2CuO4, La2CuO4+d, Ba2CuO4-d.
Michio Naito, Hideki Yamamoto, and Hisashi Sato, "Reflection High-Energy Electron Diffraction and Atomic Force Microscopy Studies on Homoepitaxial Growth of SrTiO3 (001)." To be published in Physica C. NTT Basic Research Laboratories, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-01, JAPAN; telephone +81 462 40 3516; telefax +81 462 70 2364; e-mail michio@will.br1.ntt.co.jp. Key words: SrTiO3, homoepitaxial growth, RHEED, RHEED oscillation, AFM, step-and-terrace structure, layer-by-layer growth, step-flow growth, Stranski-Krastanov growth, 3D island growth.
E. Piegari, V. Cataudella, and G. Iadonisi, "The Boson-Fermion Model in the Mean-Field Approximation." To be published in Physica C (in press). Contact V. Cataudella, I.N.F.M., Unita di Napoli, Dip. di Scienze Fisiche, Mostra D'Oltremare pad. 19, I-80125 Naples, ITALY. Key words: boson, fermion, mean-field approximation.
V. Yu. Pomjakushin, A. A. Zakharov, A. M. Balagurov, A. Schenck, F. N. Gygax, A. Amato, D. Herlach, A. I. Beskrovny, V. N. Duginov, Yu. V. Obukhov, A. V. Pole, V. G. Simkin, A. N. Ponomarev, and S. N. Barilo, "Microscopic Phase Separation in La2CuO4+x Induced by the Superconducting Transition." Preprint #E14-98-10; submitted to Phys. Rev. Lett. Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, RUSSIA.
Z. F. Ren, W. Li, D. Z. Wang, J. Y. Lao, J. H. Wang, M. Paranthaman, D. T. Verebelyi, D. K. Christen, D. F. Lee, A. Goyal, and D. M. Kroeger, "In-Plane Aligned Superconducting Tl0.78Bi0.22Sr1.6Ba0.4Ca2Cu3O9 Films on Rolling Assisted Biaxially Textured Substrates (RABiTS)." Submitted to Appl. Phys. Lett. Materials Synthesis Laboratory, Departments of Physics and Chemistry and Center for Advanced Photonic and Electronic Materials (CAPEM), State University of New York at Buffalo, Buffalo, NY 14260-3000; telefax (716) 645-6949; e-mail zren@acsu.buffalo.edu.
S. B. Roy, P. Chaddah, and L. E. DeLong, "Possibility of a First-Order Transition in the Magnetization Study of the Anomalous Superconducting Mixed State of CeRu2." To be published in Physica C (in press). Low Temperature Physics Group, Centre for Advanced Technology, Indore 452013, INDIA. Key words: first-order transition, CeRu2, superconducting mixed state.
I. Schuerrer, E. Schachinger, and J. P. Carbotte, "Optical Conductivity of Superconductors with Mixed Symmetry Order Parameters." To be published in Physica C (in press). Contact E. Schachinger, Institut fuer Theoretische Physik, Technische Universitaet Graz, Petersgrasse 16, A-8010 Graz, AUSTRIA; telephone +43 316 873 8176; telefax +43 316 873 8678. Key words: optical conductivity, superconductors, mixed symmetry order parameters. 74.20.Fg; 74.25.Nf; 74.72.-h.
H.-B. Schuettler, C. Groeber, H. G. Evertz, and W. Hanke, "Overscreening in Hubbard Electron Systems." Center for Simulational Physics, Department of Physics and Astronomy, University of Georgia, Athens, GA 30602; H. G. Evertz's e-mail at Universitaet Wuerzburg evertz@physik.uni-wuerzburg.de; preprint also available at cond- mat@xxx.lanl.gov (#9805133). 74.20.-z; 74.20.Mn.
A. Sherman and M. Schreiber, "Spectral and Magnetic Properties of the Two-Dimensional t-J Model in the Quantum Disordered Regime." To be published in Physica C (in press). Institute of Physics, University of Tartu, Riia 142, EE-2400 Tartu, ESTONIA; telephone +372 7 428164; telefax +372 7 383033; e-mail alexei@fi.tartu.ee. Key words: t-J model, pseudogap, magnetic properties. 74.25.Ha; 74.25.Jb; 71.27.+a; 74.72.-h.
C. T. Shih, Y. C. Chen, H. Q. Lin, and T. K. Lee, "d-Wave Pairing Correlation in the Two-Dimensional t-J Model." To be published in Phys. Rev. Lett. National Center for High-Performance Computing, Hsinchu, Taiwan, REPUBLIC OF CHINA; e-mail c00cts00@nchc.gov.tw; preprint also available at cond-mat@xxx.lanl.gov (#9807027). 74.20.-z; 71.27.+a; 74.25.Dw.
T. Tatsuki, S. Adachi, T. Tamura, and K. Tanabe, "High Pressure Synthesis of Sr2CuO2+dCl2-d' Compound." To be published in Physica C (in press). Superconductivity Research Laboratory, International Superconductivity Technology Center (ISTEC), 10-13 Shinonome 1-chome, Koto-ku, Tokyo 135-0062, JAPAN; telephone +81 3 3536-5703 through -5705; telefax +81 3 3536-5714 or -5717. Key words: apical chlorine, superconductor, high-pressure synthesis.
Masahisa Tsuchiizu and Yoshikazu Suzumura, "Two-Coupled Chains with Spin-Anisotropic Backward Scattering." To be published in Physica C (in press). Contact Yoshikazu Suzumura, Department of Physics, Nagoya University, Nagoya 464-8602, JAPAN; telephone +81 52 789 2437; telefax +81 52 789 2932; e-mail e43428a@nucc.cc.nagoya-u.ac.jp. Key words: d- wave superconductor, fluctuation effects, Hubbard model, organic superconductor, spin density wave. 71.10.Hf; 74.70.Kn; 75.30.Fv; 75.30.Gw.
F. Vasiliu, V. Sandu, P. Nita, S. Popa, Elena Cimpoiasu, and Mihaela Carmen Bunescu, "The Role of Radiation Damage Structure and Fine Scale Precipitation in the Pinning Improvement of Thermal Neutron Irradiated Lithium Fluoride-Doped YBa2Cu3O7-x." To be published in Physica C (in press). National Institute of Materials Physics, P.O. Box MG-7, R-76900 Bucharest-Magurele, ROMANIA; telefax +40 41 423 1700. Key words: high- Tc superconductors, YBa2Cu3O7-x, Li doping, neutron irradiation, critical currents, TEM observations. 74.60.Jg; 61.80.Hg.
N.V.N. Viswanath, T. Rajasekharan, Latika Menon, N. Harish Kumar, S. K. Malik, G. K. Dey, and D. D. Upadhyaya, "Effect of Sm2BaCuO5 Addition on the Properties of Melt Processed SmBa2Cu3Oy." To be published in Physica C (in press). Contact T. Rajasekharan, Defence Metallurgical Research Laboratory, P.O. Kanchanbagh, Hyderabad 500 058, INDIA; telephone +91 40 444 0051; telefax +91 40 444 1439; e-mail vsbsp@uohyd.eynet.in. Key words: melt processing, solid-liquid melt- growth route, SmBa2Cu3Oy.
Andreas Volmer and Moshe Schwartz, "Van der Waals Interaction Between Flux Lines in High-Tc Superconductors: A Variational Approach." Institut fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Str. 77, D-50937 Koeln, GERMANY; e-mail av@thp.uni-koeln.de; preprint also available at cond-mat@xxx.lanl.gov (#9806298). 74.60.Ec; 74.72.Hs.
Jiri Vrba and Jim McKay, "Character and Acquisition of Multichannel Biomagnetic Data." To be published in Appl. Supercond. (in press). CTF Systems Inc., #15-1750 McLean Ave., Port Coquitlam, B.C., CANADA V3C 1M9.
S. J. Wang, X. W. Cao, J. Fang, J. L. Chen, K. B. Li, and Z. H. Wang, "Resistive Transition of (YBa2Cu3O7)24/(PrBa2Cu3O7)2 Multilayer in High Magnetic Field." To be published in Physica C (in press). High Magnetic Field Laboratory, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, PEOPLE'S REPUBLIC OF CHINA. Key words: resistive transition, anisotropy, activation energy. 74.60.Ge; 74.60.Ec; 74.76.Bz; 74.25.Fy.
B. D. Weaver, E. M. Jackson, and G. P. Summers, "Effect of Proton Irradiation on the Resistance in Tl2Ba2CaCu2O8 Josephson Junctions and Thin Films." To be published in Physica C (in press). Naval Research Laboratory, Code 6615, Washington, DC 20375-5345; telephone (202) 767- 5456; telefax (202) 404-8076. 61.80.-x; 74.50.+r; 74.90.+n.
C. Weber, A. M. Klushin, M. Darula, R. Semerad, W. Prusseit, and H. Kohlstedt, "Large Shapiro Steps and Wide Junction Behavior in HTS Josephson Junctions at Nitrogen Temperatures." To be published in Appl. Supercond. (in press). Forschungszentrum Juelich GmbH, D-52425 Juelich, GERMANY; telephone +49 2461 612348; telefax +49 2461 612440; e-mail c.weber@fz-juelich.de.
Balam A. Willemsen, K. E. Kihlstrom, T. Dahm, D. J. Scalapino, B. Gowe, D. A. Bonn, and W. N. Hardy, "Microwave Loss and Intermodulation in Tl2Ba2CaCu2Oy Thin Films." To be published in Phys. Rev. B. Superconductor Technologies, 460 Ward Dr., Suite F, Santa Barbara, CA 93111-2310; telephone (805) 683-7646; telefax (805) 967-0342. 74.72.Fq; 74.76.Bz; 84.40.Dc; 74.60.Jg.
Xiao-Jing Wu, T. Tatsuki, S. Adachi, and K. Tanabe, "New Type 2212 Structure Discovered in Tl-Hg-Ba-Cu-O System." To be published in Physica C (in press). Superconductivity Research Laboratory, International Superconductivity Technology Center (ISTEC), 10-13 Shinonome 1-chome, Koto-ku, Tokyo 135, JAPAN; telephone +81 3 3536-5703 through -5705; telefax +81 3 3536-5714 or -5717. Key words: 2212 structure, EDX composition analysis, TEM observation.
K. Yamagiwa and I. Hirabayashi, "Structural and Superconducting Properties of Biaxially Aligned Yb123 Films Prepared by Chemical Solution Deposition." To be published in Physica C (in press). Superconductivity Research Laboratory, International Superconductivity Technology Center (ISTEC), Div. VIII, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8587, JAPAN; telephone +81 52 871 4002; telefax +81 52 871 4090; e- mail yamagiwa@istec.or.jp. Key words: Yb123 films, chemical solution deposition, in-plane alignment, oxygen partial pressure, metal naphthenates.
Anatoley T. Zheleznyak, Victor M. Yakovenko, and H. D. Drew, "Magnetoresistance of YBa2Cu3O7 in the 'cold spots' model." Center for Superconductivity Research and Department of Physics, University of Maryland, College Park, MD 20742-4111; Victor M. Yakovenko's e-mail yakovenk@physics.umd.edu; preprint also available at cond- mat@xxx.lanl.gov (#9807058). 72.15.Gd; 72.15.Lh; 74.72.-h; 74.25.Fy.
COMING EVENTS (An * indicates a previously listed event.)
*Sept. 14 - 20, 1998: Advanced Methods in Surfaces and Interfaces: Summer School, Institut d'Etudes Scientifiques de Cargese, Universite de Corte - Universite de Nice/Sophia-Antipolis - UMS 820 CNRS, Cargese, Corse, France. The objective of the school (limited to 80 participants/students) is to present and discuss the most recent advances in surface and interface science. Speakers will present pedagogical lectures on advanced experimental and theoretical studies of semiconductors, metals, superconductors, and biomaterials. Topics will include: optical methods, spectromicroscopy, synchrotron-radiation- related techniques, electron microscopy, electron holography, x-ray diffraction, scanning tunneling microscopy and spectroscopy (STM, STS), photoreaction and photostimulated desorption, helium atom beam scattering, dichroism, absorption spectroscopy, STM image simulation, and new generation synchrotron sources. Presentation of few selected contributed papers will also be arranged. Registration fee: FF 3,500 (participants), FF 2,500 (students). The fees include accommodation, lunch, and coffee breaks. For information, contact Claude Zwicky, IPA- EPFL, CH-1015 Lausanne, Switzerland; telefax +41 21 693 4666; e-mail zwicky@ipasg.epfl.ch; Web site http://dpwww.epfl.ch/surfaces98.
*Sept. 25 - Oct. 2, 1998: First Crete Euroconference on Anomalous Complex Superconductors (ACS-I), Heraklion, Greece. Objective is to initiate a simultaneous comparative study of characteristic anomalies of high-Tc superconductors and analogous anomalies in other "complex'' superconductors like heavy fermions, organics, fullerides, borocarbides, ruthenates, etc. In-depth simultaneous comparative analysis of all manifestations of complex behavior in the various materials will be pursued in order to "distinguish relevant from irrelevant aspects for high-Tc superconductors and to obtain some systematic theoretical understanding of the mechanisms through which this complex behavior influences Tc." For further information, contact Georgios Varelogiannis, IESL-FORTH, P.O. Box 1527, 71110 Heraklion Crete, Greece; telephone +30 81 391565; telefax +30 81 391569; e-mail varelogi@iesl.forth.gr.
*Nov. 9 - 12, 1998: 43rd Annual Conference on Magnetism and Magnetic Materials, Hotel InterContinental, Miami, Fla. This conference will include all basic and applied science and technology related to the field of magnetism. Topics are: fundamental properties and cooperative phenomena, transport properties, computational magnetics and imaging, soft magnetic materials and applications, hard magnetic materials and applications, structured materials, other magnetic materials, magnetic recording, applications, and interdisciplinary topics. For information, contact Conference Coordinators at Courtesy Associates; telephone (202) 973-8668; telefax (202) 973-8722; e-mail magnetism@courtesyassoc.com; Web site http://www.ieee.org/society/mag or http://www.aip.org/pubserv.html. (Note corrected date.)
*Nov. 16 - 19, 1998: 11th International Symposium on Superconductivity (ISS'98), Fukuoka Sunpalace Hotel, Fukuoka, Japan. Organized by the International Superconductivity Technology Center (ISTEC). Symposium will consist of oral and poster sessions and invited talks in the following topics: Physics -- theory, physical properties, and new measurement techniques; Chemistry -- new materials and syntheses, substitution, solid-state chemistry, and properties; Critical Current -- flux-pinning mechanism, vortex physics, and weak links; Wires, Tapes, and Bulk -- solid-state powder ceramics, chemical-solution processing, melting solidification, and chemical-vapor deposition; Films and Junctions -- processing, properties, lithography, junction fabrication, and physics; Device Applications -- digital, analog, SQUID, and other electronic devices; System Applications -- power, power transportation, magnets, magnetic shields, and other system applications; Standardization -- standardization for electromagnetic, mechanical, and microwave properties measurements. Will also include exhibition of materials and devices. Proceedings to be published. Official language is English. For further information, contact ISS'98 Secretariat, ISTEC, Eishin Kaihatsu Bldg. 6F, 34-3 Shimbashi 5-chome, Minato-ku, Tokyo 105- 0004, Japan; telephone +81 3 3431 4002; telefax +81 3 3431 4044.
Dec. 14 - 16, 1998: Conference on Advances in Superconductivity and Its Applications in Microwaves (ASAM'98). Intends to provide a forum to review the progress and obstacles in the field of superconductivity and to find solutions to these problems. Topics to be covered are: new superconducting materials and their novel aspects; critical currents; theoretical aspects of high-Tc superconductivity; microwave superconductivity; thin films and devices; vortex structures, pinning, and dynamics; semiconductor-superconductor microwave circuits; and other related topics such as GMR/CMR, etc. Abstract deadline, August 31, 1998; registration deadline, October 31, 1998. For further information, contact R. P. Tandon, Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India; telephone +91 11 725 7793; telefax +91 11 725 7061; e-mail ram@csec.ernet.in or chilana@csec.ernet.in.
*May 30 - June 3, 1999: 10th International Symposium on Intercalation Compounds (ISIC 10), Okazaki, Japan. Tenth in the series. Will focus on basic ideas in both the physics and chemistry of intercalation materials such as graphite, fullerenes, carbon nanotubes, chalcogenides, oxides, clays, zeolites, and other related materials. Topics to be covered: new intercalation compounds and new synthetic routes; thermodynamics, kinetics, and reaction mechanisms; structure and lattice dynamics; phase transitions; electronic properties, charge transfer, and band structures; transport properties and superconductivity; magnetic properties; electrochemical properties; intercalation electrodes for advanced batteries; and other present and potential applications. Scientific program will consist of plenary lectures as well as oral and poster sessions. Proceedings to be published as a special issue of Molecular Crystals and Liquid Crystals. Abstract deadline, December 15, 1998. For further information, contact Toshiaki Enoki, ISIC 10, Department of Chemistry, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8551, Japan; telefax +81 3 5734 2242; e-mail isic@chem.titech.ac.jp; Web site http://www.chem.titech.ac.jp/~isic/.
High-Tc Update is the high-Tc superconductivity information exchange newsletter. Please send 1) preprints, reprints, and other research reports; 2) descriptions of on-going work; 3) meeting announcements and summaries.
The information contained herein is intended for limited distribution. Readers are expected to respect the rights of the authors.
Please address all contributions and inquiries to:
Dr. Sreeparna Mitra, A219 Physics,
Ames Laboratory/Iowa State University,
Ames, Iowa 50011-3020.
Telephone: (515) 294-3877 Telefax: (515) 294-1134.
E-mail: MITRA@AMESLAB.GOV
or MITRA@IASTATE.EDU.
Project Director/Editor: Sreeparna Mitra
Science Editor: John R. Clem
High-Tc Update, Vol. 12, #15, August 1, 1998.