solid state communications an international journa { volume 78 SOLID STATE COMMUNICATIONS EDITOR-IN-CHIEF, ELIAS BURSTEIN ASSOCIATE EDITOR-IN-CHIEF, MANUEL CARDONA EDITORIAL POLICY COMMITTEE P. AIGRAIN, Chairman P. G. DE GENNES J. A. KRUMHANSL W. M. LomeR S. LUNDQVIST H. SUHL Y. ToYoZAWwA BOARD OF EDITORS V. M. AGRANOvICH, Moscow Institute of Spectroscopy of the Academy of Sciences, U.S.S.R. Academgorodok, Podolski r-n, Moscow obl. 142092, U.S.S.R. S. ALEXANDER, Jerusalem Hebrew University, Jerusalem, Israel M. BALKANSKI, Paris Laboratoire de Physique des Solides, Université Pierre et Marie Curie, 4, Place Jussieu, Tour 13 —2e Etage, 75230 Paris Cedex 05, France I. BALSLEV, Odense Fysisk Institut, Odense Universitet, DK-5230 Odense M, Denmark R. Barrie, Vancouver Department of Physics, University of British Columbia, Vancouver 8, British Columbia, Canada V6T 1W5 P. BurLet, Grenoble Centre d’Etudes Nucléaires, DRF/SPh—- MDN, 85x, 38041 Grenoble Cedex, France G. Burns, New York I.B.M., T. J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598, U.S.A. (Deputy Editor-in-Chief) M. F. Cou.ins, Hamilton Department of Physics, McMaster University, Hamilton, Ontario, Canada L8S 4M1 P. H. Depericns, Julich Institut fiir Festk6rperforschung der Kernforschungsanlage Jiilich GmbH, 5170 Jiilich 1— Postfach 1913, Federal Republic of Germany A. L. Erros, Leningrad (On leave) G. Faso., Cambridge Hitachi Cambridge Laboratory, c/o Cavendish Laboratory, Madingley Road, Cambridge CB3 OHE, U.K. R. Fiescui, Parma Istituto di Fisica, Universita degli Studi, 43100 Parma, Italy Z. Gan, Beijing Department of Physics, Peking University, Beijing 100871, People’s Republic of China C. E. T. GONCALVES DA SILVA, Laboratoire Nacional de Luz Sincrotron/CNPq/MCT, Caixa Postal 6192, Campinas 13081 SP, Brazil Campinas M. GrYNBERG, Warsaw Institute of Experimental Physics, University of Warsaw, 00-681 Warsaw, ul.Hoza 69, Poland G. GUNTHERODT, Aachen II. Physikalisches Institut, RWTH Aachen, Templergraben 55, D-5100 Aachen, Federal Republic of Germany J. JOFFRIN, Paris Université Paris-Sud, Batiment 510, 91405 Orsay, France H. Kamimura, Tokyo The Science University of Tokyo, Department of Applied Physics, Faculty of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162, Japan L. V. KELDysH, Moscow P. N. Lebedev Institute, Academy of Sciences of the U.S.S.R. Leninskii Prospect 53, 117924 Moscow, US:S.R; W. Y. Kuan, Beijing (On leave) B. Lunpevist, Goteborg Institute of Theoretical Physics, Chalmers University of Technology, S-412 96 Goteborg, Sweden A. H. MacDona_pD, Bloomington Department of Physics, Indiana University, Bloomington, Indiana 47405, U.S.A. A. A. MARADuDIN, /rvine Department of Physics, University of California, Irvine, California 92717, U.S.A. T. P. Martin, Stuttgart Max-Planck-Institut fiir Festkorperforschung, Heisenbergstrasse 1, 7000 Stuttgart 80, Federal Republic of Germany E. Mo uinari, Rome CNR Istituto ‘‘Corbino’’, Via Cassia 1216, 00189 Rome, Italy B. MUHLSCHLEGEL, Koln Institut fiir Theoretische Physik, Universitat zu K6ln, Zulpicher Str. 77, D-5000 Koln 41, Federal Republic of Germany A. Oxisi, Osaka Department of Applied Physics, Faculty of Engineering, Osaka University, Suita, Osaka 565, Japan A. Pinczuk, New Jersey Room 1D—-433, AT&T Bell Laboratories, Murray Hill, New Jersey 07974, U.S.A. C. N. R. Rao, Bangalore Indian Institute of Science, Bangalore 560012, India R. H. SitsBee, /thaca Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, U.S.A. J. Tauc, Providence Box D, Division of Engineering, Brown University, Providence, Rhode Island 02912, U.S.A. M. P. Tosi, Trieste International Centre for Theoretical Physics, P.O. Box 586, Miramare, 34100 Trieste, Italy T. Tsuzuki, Sendai Department of Physics, Faculty of Science, Tohoku University, Aoba-ku, Sendai 980, Japan D. 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Co) ) ™ The text paper used in this publication meets the minimum requirements of American National Standard for Information Sciences—Permanence of Paper for Printed Library Materials, ANSI Z39.48-1984. CONTENTS APRIL VOLUME 78, NUMBER | General Papers R. P. Vardapetyan, A. P. Hovhanesyan and Theory of self-transducer photoacoustic spectroscopy A. A. Araratyan R. W. van der Heijden, G. Chen, Simple activated iransport in ion-implanted Si:As_ at A. T. A. M. de Waele, H. M. Gijsman and temperatures below 0.5 K F. P..B. Tielen E. Lopez Olazagasti, G. H. Cocoletzi and Optical properties of bimetallic superlattices W. Luis Mochan J. Martorell, S. Klarsfeld, D. W. L. Sprung Analytical treatment of electron wave propagation in two- and Hua Wu dimensional structures I. P. Ipatova, V. A. Shchukin, Formation of strained superlattices with a macroscopic period | V. G. Malyshkin, A. Yu. Maslov and via spinodal decomposition of III — V semiconductor alloys E. Anastassakis W. Kang On the splitting of Shubnikov-de Haas oscillations in organic conductors A. P. Monkman and P. Adams Stretch aligned polyaniline films J. M. Pérez-Mato, G. Madariaga and L. Elcoro Influence of phason dynamics on atomic Debye-Waller factors of incommensurate modulated structures and quasicrystals S. A. Patil, S. M. Otari, V. C. Mahajan, Structural, IR and magnetisation studies on La*~ substituted M. G. Patil, A. B. Patil, M. K. Soudagar, copper ferrite B. L. Patil and S. R. Sawant Superconductors and Superconductivity Y. Suwa and M. Tsukada Superconductivity of thin wire networks with very small meshes H. Mori, S. Tanaka, T. Mori, Y. Maruyama, Structural and physical properties of (BEDT-TTF),Li,, H. Inokuchi and G. Saito Hg(SCN),(H,O), and a”-(BEDT-TTF),CsHg(SCN), E. J. Nicol and J. P. Carbotte D. C. Josephson current in marginal Fermi liquid model M. S. R. Rao, R. Suryanarayanan, Structural and superconducting properties of YSrBaCu,_, L. Ouhammou and O. Gorochov Al,O,.- (0<x < 0.2) R. Gaji¢, J. Schiitzmann, J. Betz, T. Zetterer, Pronounced phonon softening in the far-infrared spectra of H. H. Otto, P. E. Obermayer and K. F. Renk YBa,(Cu,_ ,Zn,),0; E. Spahn and K. Keck Anomalous resistance behaviour in the superconducting fluctuation region of thin aluminum films i Instructions for Authors on the Preparation of Camera-Ready Manuscripts for Solid State Communications iV Vol. 78, Nos. 1-12 Contents APRIL VOLUME 78, NUMBER 2 General Papers K. Suzuki, T. Enoki and K. Imaeda Synthesis, characterization and physical properties of incommensurate layered compounds (RES),TaS, (RE = rare earth metal) V. P. Godbole, S. N. Yedave, S. J. Dikshit, Evidence for significant modifications of ion induced S. M. Chaudhari, S. M. Kanetkar and processes in oxide by external electric field S. B. Ogale A. M. Sukeshini and K. Hariharan Transport and thermal properties of the solid electrolyte Ag,Cu,_,Hgl, Superconductors and Superconductivity G. A. R. Lima, A. Fazzio and R. Mota Theoretical investigation of the optical spectra of superconducting YBa,Cu,O, . S. Kazeroonian, T. K. Cheng, Probing the Fermi level of Y, _,Pr,Ba,Cu,O,_, by femtosecond S. D. Brorson, Q. Li, E. P. Ippen, X. D. Wu, spectroscopy . Venkatesan, S. Etemad, M. S. Dresselhaus and G. Dresselhaus Z. V. Popovic, A. Sacuto and M. Balkanski Raman spectra of Nd, ,,;Ce, ,,<CuO, T. Onogi, R. Sugano and Y. Murayama Power-law resistive behavior of two-dimensional Josephson junction array with bond defects: dynamic simulation and its relevance to high-T, oxides J. Bonéa, P. PrelovSek and I. Sega ’ Ground state properties in the t—J model at high doping R. Kuentzler, G. Pourroy, A. Tigheza and Effect of preparation method and impurities on the specific Y. Dossmann heat and magnetic susceptibility of Nd,CuO, General Papers (contd) G. M. Niftiyev, F. B. Askerov and Electrical properties of SmGa,S, single crystal O. B. Tagiyev Tsai-Sheng Gau and Jiang-Tsu Yu Electron paramagnetic resonance of Cu’* in KHCO, crystals K. Nakagawa, B. Rakvin and N. S. Dalal Temperature dependence of large hyperfine coupling: SeO}” radical and evidence against a 310K phase transition in KH,PO, G. Gangadher Reddy and A. Ramakanth Thermal expansion of mixed valence compounds Wang Jiajian, Song Yumei, Cheng Xingkui Study of persistent photoconductivity and Staebler — Wronski and Dai Guocai effects on a-Si: H/a-SiY :H semiconductor superlattice I. Pelant and J. Hala Note on coexistence of free and self-trapped excitons in AgCl N. H. Lu, P. M. Hui and T. M. Hsu Wannier exciton binding energies in GaAs/Al,Ga,_,As quantum wells A. Nayak, D. R. Rao and H. D. Banerjee Derivative spectra of polycrystalline Zn,P, thin films J. Kudrnovsky and N. E. Christensen Electronic structure and properties of transition-metal disilicides CoSi,, NiSi, and their alloys Co,Ni, _,Si, C. Ghezzi, R. Mosca, A. Bosacchi, S. Franchi, Evidence for non-equilibrium free electron density in AlGaAs E. Gombia and L. E. Vanzetti at low temperatures Vol. 78, Nos. 1-12 Contents G. E. W. Bauer 163 Exciton unbinding in a confined Fermi sea A. Lorek, N. Grewe and F. B. Anders 167 Magnetotransport in heavy fermion compounds Z. Kuéera, P. Hlidek, P. Héschl, V. Koubele 173 The absorption edge in p-type Hg,_,Cd,Te (x ~0.2) and M. Zvara APRIL VOLUME 78, NUMBER 3 General Papers A. Chmel, E. K. Mazurina et V. S. Shashkin 177 Déplacement du pic Boson dans le spectre Raman de Ia silice préparée a partir de gels . Chevalier and J. Dumas 181 Mdossbauer study of the Peierls transition in the quasi-two dimensional molybdenum oxide y-Mo,0O,, . V. B. Sarkissian and B. D. Rainford Neutron spin echo studies in Pd—Mn alloys . Buckthought, R. Boulet, A. Sachrajda, Activation measurements of the fractional quantum Hall . Wasilewski, P. Zawadzki and F. Guillon effect in a tilted magnetic field as a function of electron density . Jeandey, J. L. Oddou, J. L. Mattei and Mossbauer investigation of the pyrrhotite at low temperature . Fillion . Giannetta and L. Wilen Nonequilibrium melting of the two dimensional electron crystal . O. Gogolin and A. S. Ioselevich Anomalous hopping magnetoresistance in semiconductors with complex magnetic structure: application to lightly doped La,CuO, V. Riede, H. Neumann, V. Kramer and Infrared and Raman spectra of CdIn,Te, M. Kittel L. Jaeger Resonant transmission through a double-point contact device in high magnetic field C. J. Chou and G. F. Neumark Acoustic phonon-broadened line shape of don— aoccerpto r pair spectra — A first-principles study Superconductors and Superconductivity V. N. Kostur and S. E. Shafranjuk The met—a olxid e superconducting state symmetry and J— V characteristics of the tunnel junctions S. Yoksan Isotope effect in high-7. superconductors M. Guillot, B. Souletie, J. L. Tholence, Magnetic properties and critical current densities of large H. Noél, J. C. Levet, M. Potel and crystals of YBa,Cu,O, P. Gougeon M. V. Krasin’kova and B. Ya. Moizhes 241 On anomalously high 7. in some cuprates and nickelates E. Yap and G. Bergmann 245 Transition temperature of coupled thin superconducting films APRIL VOLUME 78, NUMBER 4 General Papers R. Osorio, S. Froyen and A. Zunger 249 Superlattice energetics and alloy thermodynamics of GaAs/Ge =. Vol. 78, Nos. 1-12 Contents B. Fabritchnyi, L. P. Fefilatiev, 257 Etude par spectrometrie Méssbauer des etapes initiales du Q . Demazeau, J. Etourneau, V. V. Avdeev, processus d’enrobage des particules aciculaires de Fe,O, , par F. Levina, V. V. Popov et coprecipitation des ions Co’* et Fe’* . A. Kremenchugskaya Liu, R. S. Zheng, S. Takaoka, K. Murase, Fluctuations, localization effect and AB effect in mesoscopic Gamo and S. Namba structures of bismuth . Filipponi, A. Di Cicco, T. A. Tyson and ‘*Ab-initio’’ modelling of X-ray absorption spectra R. Natoli SOMa PSe. Abkowitz and M. Stolka Electronic transport in aliphatic polysilylenes and poly- germylenes . J. Chang Atomic structure of shallow acceptor- and donor-hydrogen complexes in GaAs . Takagahara Dependence on dimensionality of excitonic optical nonlinearity in quantum confined structures Superconductors and Superconductivity S. B. Ogale, S. T. Bendre, P. Guptasarma Influence of magnetic impurities on current transport in and M. S. Multani epitaxial thin films of Y,Ba,Cu,O,_, B. Friedl, C. Thomsen, H.-U. Habermeier Intensity anomalies of Raman-active phonons in the and M. Cardona superconducting state of YBa,Cu,O,_, Shiyang Tian, Jingqing Liu, Meihua Li and Further evidence for strong electron—phonon interaction Zhong-Xian Zhao origin of low frequency structure of infrared reflectance in high-7, superconductors A. Furusaki and M. Tsukada DC Josephson effect and Andreev reflection R. P. Vasquez, A. Gupta and A. Kussmaul X-ray photoelectron spectroscopy study of chemically-etched Nd —Ce-—Cu-—O surfaces Shi Da-ning, Shi Wei and Li Zheng-zhong Hole pairing in the RVB state General Papers (contd) Ying-chang Yang, Xiao-dong Zhang, Lin-shu Neutron diffraction study of the nitride YTiFe,,N, Kong, Qi Pan, Sen-lin Ge, Ji-lian Yang, Yong-fan Ding, Bai-sheng Zhang, Chun-tang Ye and Lan Jin Ying-chang Yang, Xiao-dong Zhang, New potential hard magnetic material — NdTiFe,,N, Lin-shu Kong, Qi Pan and Sen-lin Ge A. Stesmans Shallow donor in buried oxide Si-on-insulator structures revealed by y-irradiation-induced electron spin resonance activation i Author Index Nos 1-4 VOLUME 78, NUMBER 5 General Papers B. Samson, S. R. P. Smith, C. T. Foxon, 325 Interface effects on phonons in superlattices D. Hilton and k. J. Moore I. T. Belash, O. I. Barkalov, A. I. Kolesnikov, 331 Inelastic neutron scattering in amorphous and crystalline E. G. Ponyatovskii and M. Prager phases of Zn-—Sb and Cd-—Sb systems produced by thermobaric treatments Vol. 78, Nos. 1-12 Contents Vii kK. Harigaya and A. Terai 335 Metal-insulator transition in doped conducting polymers: disappearance of electronic gap with persisting bond alternation S. G. Tikhodeev Tamm minibands in superlattices J. F. Young, P. J. Kelly, N. L. Henry and Carrier density dependence of hot-electron scattering rates in M. W. C. Dharma-wardana quasi-equilibrium electron-hole plasmas E. Anastassakis In-plane misfit strains in heterostructures and superlattices: arbitrary direction of growth J. Masek Electronic structure and exchange interactions in diluted semimagnetic semiconductors (Zn,Co)Se and (Zn,Mn)Se H. Dreyssé, L. T. Wille and D. de Fontaine Microscopic theory of surface segregation in binary alloys P. Bordet, D. E. Cox, G. P. Espinosa, Synchrotron X-ray powder diffraction study of the phase J. L. Hodeau and M. Marezio I’compound: SnLa,Rh,Sn,, Superconductors and Superconductivity V. G. Orlov The crystalline electric field and Nd antiferromagnetism in Nd,CuO, P. I. Arseyev and B. A. Volkov Resonance impurities in superconductors R. C. Casella A theoretical model for the tunneling-gap anisotropy observed in layered copper-oxide high-temperature superconductors A. L. U. Roberts, S. C. Mayo, N. C. Woolsey, Application of synchrotron anomalous scattering to study the A. M. Glazer and K. P. J. O’Reilly modulated structure of Bi,Sr,CaCu,O, M. DeMarco, Min Qi, J. H. Wang, Oxygen removal by hydrogen gas in ‘Fe doped YBa,Cu,O, M. Chaparala and M. J. Naughton Tu Heng-Yong and Wu Jin-Di A new superconductor in the system Pb-—Sr—B a-—La- Cu-O R . Akis and J. P. Carbotte Damping effects on NMR in superconductors S. C. Bhargava, J. S. Chakrabarty, Preparation of 2212 phase of Bi superconductor with 7. of R. Sharma, C. V. Tomy and S. K. Malik 92K K . N. Shrivastava Formation of the flux-quantized oscillations from the Cu’* electron — paramagnetic — resonance states in the microwave absorption in high-temperature superconductors . M. Balagurov, J. Piechota and Neutron powder diffraction on YBa,(Cu, ,“Ni,),O;_, . Pajaczkowska . A. Ladds, G. A. Saunders, P. J. Ford, Magnetic origins of the phase transitional behaviour at 200 K . P. Almond, Chang Fanggao, Z. Othaman, in Ca, <Zn, <Fe,O, . J. Bending, S. Smith, B. F. Chapman, . A. L. Sullivan, Ll. Manosa and Q. A. Pankhurst J. P. Sanchez, K. Tomala and A. Szytula 'SGd Mossbauer study of GdMn,Ge, General Papers (contd) P. Heszler, L. B. Kiss and M. Torok Model for the UV laser ablation of polymers in the low- fluence limit S. Modak and S. Gangopadhyay Surface segregation of Pt — Ni alloys Viil Vol. 78, Nos. 1-12 Contents J. Cen, K. Kempa and P. Bakshi 433 Amplification of plasma modes in semiconductor hetero- structures Ji-Zhong Xu 439 Radiation of a kink in hydrogen-bonded chains U. Konig, B. Ginatempo, J. Redinger and 445 A fully relativistic study of angle-resolved photoemission of P. Weinberger the Au (1 1 1) surface R. D. S. Yadava and A. V. R. Warrier 449 On the nature of alloying in HgTe —CdTe solid solutions at low temperatures from electrode potential measurements . J. W. Zandvliet, W. J. Caspers and 455 Order — disorder phase transition of the Ge(0 0 1) surface . van Silfhout A. Krapf, G. Denninger, H. Pascher, 459 Optically detected nuclear magnetic resonance and Knight 3. Weimann and W. Schlapp shift in Al,Ga, ,As/GaAs heterostructures . S. Crisp, D. Haneman and J. W. Chu 465 Valence band structure of CulnSe, by soft X-ray spectroscopy . Miller and H. D. Lutz 469 Raman spectra of MnSe,, MnTe,, RuTe,, and OsTe, . Moze, R. M. Ibberson and 473 Neutron diffraction investigation of Si site preference in .. H. J. Buschow RENi,,Si, compounds MAY VOLUME 78, NUMBER 6 General Papers Z. Shuai, D. Beljonne and J. L. Brédas SSH-Hamiltonian description of the electronic structure and vibrational properties of polyparaphenylene vinylene A. Salinas-Sanchez, R. Sdez-Puche, Structural characterization of R,BaNiO, (R = Tm and Yb): J. Rodriguez-Carvajal and J. L. Martinez polymorphism for R = Tm R. Tanaka, S. Nakamichi, S. Endo, H. Wada, Pressure induced ferromagnetism in TbMn, M. Shiga and F. Ono R. L. Williams, P. Coleridge, Silicon atomic plane doping in MBE grown InAs/GaAs Z. R. Wasilewski, M. Dion, A. Sachrajda and S. Rolfe M. S. Somayazulu, P. U. M. Sastry and Anomalous changes in lattice parameters, specific heat, and V. K. Wadhawan loss factor in potassium titanyl phosphate at 324 K E. R. Giessinger, R. Braunstein, E. Ladizinsky, Raman spectra of ferromagnetic Lay Srp ,Cu,Mn,_,O, mixed L. Haupt, J. W. Schiinemann, K. Barner, crystals U. Sondermann and A. F. Andresen Superconductors and Superconductivity Y. Koike, N. Watanabe, T. Noji and Y. Saito Effects of the Cu-site substitution on the anomalous x dependence of 7, in La,_,Ba,CuO, V. V. Gridin, T. W. Krause, P. K. Ummat and Magnetic field dependent width of the resistive transition in W. R. Datars superconducting Bi, ,.Pb, ,Sr,Ca,Cu,O, General papers (contd) A. S. Nasibov, P. V. Shapkin, Spectroscopic investigations of semiconductor solid solutions J. V. Korostelin, J. A. Vlasov, L. S. Markov, with structural phase transition (Zn,Cd, _,-Se system) A. I. Maslov and D. L. Fedorov . 78, Nos. 1-12 Contents J. S. Nkoma 525 Surface modes of coupled sphere systems V. 1. Timoschuk and E. A. Rozenberg 531 Magnetic phase transitions of é-Mn,Ge, in magnetic fields up to 25 T J. Lukose and B. Pradeep 535 Electrical and optical properties of bismuth sulphide [Bi.S,] thin films prepared by reactive evaporation H. H. Joshi, R. B. Jotania, R. G. Kulkarni 539 “Fe Mossbauer and magnetic studies on the spinel system and R. V. Upadhyay Co, ' ,Ge,Fe, »O, C. D. Kourkoutas, J. Novac, M. Kuliffayova, 543 Transport properties of praseodymium doped p-type G. J. Papaioannou, P. Kordos and In, <,¥Gay4,As layers V. Ioannou-Sougleridis M. Ichikawa, T. Gustafsson and I. Olovsson Low-temperature phase transition in Cs,D(SeO,), R. Kawashima 553 Dependence of a.c. conductivity on temperature and frequency in an europium nitrate crystal S. Kondo, T. Itoh, T. Saito and M. Mekata 557 Well defined amorphous to crystal transformation of cold condensed TIC! films S. Rahman and T. W. Miiialisin 561 Evolution from a weak to a concentrated Kondo behavior in Ce(Tl, ,In,),; system T. J. Bastow, S. L. Segel and K. R. Jeffrey 565 Antiferroelectric transition in KOH(D): a 7H and “K NMR study M. P. Park, M. Nitta and T. Itoh 569 Electricai characteristics of amorphous GaAs,P, , films formed by ion beam sputter deposition A cumulative Author Index appears in Numbers 4, 8 and 12 of each Volume VOLUME 78, NUMBER7 General Papers T. Bouhacina, G. Ablart, J. Pescia and Spin-lattice relaxation in glasses doped with Fe,O, Y. Servant M. L. Bansal, A. K. Sood and M. Cardona Strongly dispersive low frequency Raman modes in germanium Z. W. Lu, S.-H. Wei, A. Zunger and Ground state structures of intermetallic compounds: a first- L. G. Ferreira principles Ising model G. M. Roesler, Jr and P. M. Tedrow Magnetotransport behavior of heavy fermion thin films P. U. M. Sastry Bond susceptibilities and linear electro-optic properties of KTiOPO, A. R. Law, H. P. Hughes, P. T. Andrews On the unoccupied electronic states of Hf,Ti,_,Se, alloys and F. A. Lévy Superconductors and Superconductivity Li Youmo, Li Yanrong and Hong Guangyan Superconductivity in Bi,;Pbo,Sb,Sr,Ca,Cu,0, system (x = 0-0.32) Xx Vol. 78, Nos. 1-12 Contents Qing-rong Feng, Han Zhang, Sun-qi Feng, 609 The process of forming 2223 phase from 2212 phase in Bi(Pb)- Xing Zhu, Ke Wu, Zun-xiao Liu and Sr-Ca-Cu-O system Li-xin Xue A. Chakravarti, R. Ranganathan, AC susceptibility of high temperature superconductor in BCS C. D. Mukherjee and N. Chatterjee model B. Loegel, D. Bolmont, H. Dalderop and Homogeneity of high and low temperature superconducting A. Mehdaoui compounds in relation with magnetic characterization K. Osuch Symmetry changes at the Néel point in the high-temperature superconductor GdBa,Cu,O,_, O. Llopis, T. Parra, J. C. Ousset, Comparative study of microwave surface impedance of high D. B. Chrisey, J. S. Horwitz and T. superconductor samples J. Graffeuil T. Freltoft, H. J. Jensen and P. Minnhagen Evidence for intrinsic criiical current density in high T, superconductors Genera! Papers (contd) M. Sancrotti, L. Duo’, R. Cosso, S. D’Addato, 641 Unoccupied 3d-derived states in Ni silicides via Ni L,, X-ray S. Iacobucci, G. Panaccione, A. Ruocco, absorption spectroscopy S. Nannarone, M. Surman, P. Unsworth and P. Weightman R. Staske, P. Frobel, M. v. Dirke, S. Miiller The fluorescence of Eu*? in lithium tungstate borate glasses and K. Barner A. Kumar, S. Kumar and R. Arora Space charge limited conduction in Ge,Seyw , G. Pastori Parravicini, L. Resca, R. D. Graft Intervalley interference and lattice relaxation in DX centers and D. J. Lohrmann C. Testelin, C. Rigaux, A. Mycielski, Exchange interactions in CdFeTe semimagnetic semicon- M. Menant and M. Guillot ductors R. I. Devlen, G. S Kanner, Z. Vardeny and Picosecond photomodulation spectra of a-Si:H in the small J. Tauc signal limit M. Albrecht, U. Gradmann, Th. Reinert and Scattering phases in low energy electron diffraction from spot L. Fritsche profile analysis and from multiple scattering theory MAY VOLUME 78, NUMBER 8 General Papers S. Nomura and T. Kobayashi 677 Nonparabolicity of the conduction band in CdSe and CdS,Se,_, semiconductor microcrystallites M. Anagnostou, C. Christides and D. Niarchos 681 Nitrogenation of the RFe,Mo, (R = rare earth) compounds with ThMn,, type structure S. A. Cannas, F. A. Tamarit and C. Tsallis 685 A generalised Hubbard Hamiltonian: influence of temperature and fractality N. S. Murthy, R. H. Baughman, 691 A hexagonal structure for alkali-metal doped poly(p- L. W. Shacklette, H. Fark and J. Fink phenylene)