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The aim of the workshop was to bring together specialists in various fields where non-exponential relaxation is observed in order to compare models and experimental results and to examine the general physical principles governing this type of behaviour. Non-exponential relaxation is found in extremely diverse physical systems all of which can be classified as complex. The form of the relaxation is generally parametrized using logarithmic, algebraic or stretched exponential decay forms. The conceptually simplest mechanism for the non-exponential decay is a spectrum of relaxation rates due to non-interacting units each of which relaxes with a different intrinsic time constant. Clear experimental examples can be given where for instance the relaxation of a collection of isolated polymer molecules leads to an overall stretched exponential decay. Non-exponential relaxation is observed in all strongly interacting complex systems (structural glasses, spin glasses, etc...) where each elementary unit is in interaction with many other units.

The research of unitary concepts in solid state and molecular chemistry is of current interest for both chemist and physicist communities. It is clear that due to their relative simplicity, low­ dimensional materials have attracted most of the attention. Thus, many non-trivial problems were solved in chain systems, giving some insight into the behavior of real systems which would otherwise be untractable. The NATO Advanced Research Workshop on'Organic and Inorganic Low-Dimensional Crystalline Materials'was organized to review the most striking electronic properties exhibited by organic and inorganic sytems whose space dimensionality ranges from zero (Od) to one (1d), and to discuss related scientific and technological potentials. The initial objectives of this Workshop were, respectively: i) To research unitary concepts in solid state physics, in particular for one dimensional compounds, ii) To reinforce, through a close coupling between theory and experiment, the interplay between organic and inorganic chemistry, on the one hand, and solid state physics on the other, iii) To get a salient understanding of new low-dimensional materials showing'exotic'physical properties, in conjunction with structural features.

This conference is the second on the Science and Technology of Thin Film Superconductors. It proved to be an excellent forum for these specialists in thin film superconductivity. The conference, held April 30-May 4, 1990, in Denver, Colorado, hosted 170 researchers from 17 countries. The response to the conference again emphasized the need for a meeting devoted to the science and technology of thin film superconductors. The breadth of artic1es and advances made in this technology since the first conference in November 1988, reflect on the maturity of the topic. These proceedings contain artic1es on deposition methods by sputtering, e1ectron beam evaporation, resistive evaporation, laser ablation, chemical vapor deposition and electrodeposition, and on other studies related to substrates, thermodynamics of formation, grain boundaries and weak links, characterization, and some practical applications. The program committee was pleased with the quality of the publications and contributed articles. This conference was highlighted by a fuU day dedicated to presentations from the federallaboratories, discussing a wide range of topics on the fabrication, characterization, and theory of high-temperature superconductor thin films. Other highlights at the conference dealt with (1) critical parameters or problems in measuring critical current density and other important parameters, and (2) problems of scale-up, reproducibility, and amenability to device fabrication. It became evident from the presentations that three issues were developing into critical issues for the ultimate practical application of high­ temperature superconductor thin films.

What is a supermaterial? A concise definition is by no means obvious, but a clue can be obtained from the topics discussed here.. In addition to superconductors, the reader will encounter magnetic effects of many kinds, including giant and even colossal ones, organic conductors, photoconductors, and even 400-year-old Japanese ceramics. Processing is a prominent pursuit in supermaterials research, especially but not exclusively of the superconductors. The papers on characterisation and theory break new ground, particularly in pursuit of new optoelectronic phenomena. The parade of new materials recently synthesised, often containing four or more elements, is surprising. But it is in it reporting of new applications that the book stands out: from circuits to sensors, supermaterials are making their impact on society.

Systems with competing energy scales are widespread and exhibit rich and subtle behaviour, although their systematic study is a relatively recent activity. This text presents lectures given at a NATO Advanced Study Institute reviewing the current knowledge and understanding of this fascinating subject, particularly with regard to phase transitions and dynamics, at an advanced tutorial level. Both general and specific aspects are considered, with competitions having several origins; differences in intrinsic interactions, interplay between intrinsic and extrinsic effects, such as geometry and disorder; irreversibility and non-equilibration. Among the specific physical application areas are supercooled liquids and glasses, high-temperature superconductors, flux or vortex pinning and motion, charge density waves, domain growth and coarsening, and electron solidification.

The on-going developments, and the recent achievements of the superconducting electronics (especially in the field of Josephson junctions and the inherent nonlinear dynamics) inspired us to organize a conference where different groups working on the subject could meet and discuss the latest results of their investigations. This idea was realized as two joint workshops, the NATO Advanced Research Workshop on Superconducting Electronics with Prof. N.F. Pedersen as chairman, and the 2nd Workshop on Josephson Devices, with Profs. G. Costabile and M. Russo as chairmen, held in Capri, Italy on September 3-7, 1990. The Workshops were very successful. About 70 scientists from 12 countries (Denmark, France, Germany, Greece, Italy, Japan, People's Republic of China, Sweden, United Kingdom, USA, USSR, and Venezuela) enjoyed the many interesting and mostly informal occasions for scientific exchanges as well as the very pleasant weather of Southern Italy. We are very grateful to the Institutions which made possible the realization and the success of the conference with their financial support : NATO Science Committee through the NATO International Scientific Exchange Programmes, University of Salerno, and Istituto di Cibernetica of the Consiglio Nazionale delle Ricerche (C.N.R.) of Italy. The conference was held under the auspices of the Progetto Finalizzato'Superconductive and Cryogenic Technologies'of C.N.R. Finally special thanks go to our Conference Secretary Anna Maria Mazzarella for carrying out most of the organizative work, and for her continuous'on stage'support in solving all the problems which inevitably arise in such occasions.

The book covers different aspects of the chemistry and physics of molecular materials, including organic synthesis of specific organic donors and ligands, organic metals and superconductors, molecule-based magnets, multiproperty materials and organic-inorganic hybrids. The 17 chapters are written by some of the most authoritative authors in their field. The two last chapters are devoted to molecular electronics and devices, in particular the achievements and potential for applications. An excellent work for all students and researchers in organic conductors, superconductors and molecule based magnets.

One of the most spectacular consequences of the description of the superfluid condensate in superfluid He or in superconductors as a single macroscopic quantum state is the quantization of circulation, resulting in quantized vortex lines. This book draws no distinction between superfluid He3 and He4 and superconductors. The reader will find the essential introductory chapters and the most recent theoretical and experimental progress in our understanding of the vortex state in both superconductors and superfluids, from lectures given by leading experts in the field, both experimentalists and theoreticians, who gathered in Cargèse for a NATO ASI. The peculiar features related to short coherence lengths, 2D geometry, high temperatures, disorder, and pinning are thoroughly discussed.

This volume is based on the proceedings of the NATO-sponsored Advanced Studies Institute (ASn on The New Superconducting Electronics (held 9-20 August 1992 in Waterville Valley, New Hampshire USA). The contents herein are intended to provide an update to an earlier volume on the same subject (based on a NATO ASI held in 1988). Four years seems a relatively short time interval, and our title itself, featuring The New Superconducting Electronics, may appear somewhat pretentious. Nevertheless, we feel strongly that the ASI fostered a timely reexamination of the technical progress and application potential of this rapid-paced field. There are, indeed, many new avenues for technological innovation which were not envisioned or considered possible four years ago. The greatest advances by far have occurred with regard to oxide superconductors, the so-called high­ transition-temperature superconductors, known in short as HTS. These advances are mainly in the ability to fabricate both (1) high-quality, relatively large-area films for microwave filters and (2) multilayer device structures, principally superconducting-normal-superconducting (SNS) Josephson junctions, for superconducting-quantum-interference-device (SQUID) magnetometers. Additionally, we have seen the invention and development of the flux-flow transistor, a planar three-terminal device. During the earlier ASI only the very first HTS films with adequate critical-current density had just been fabricated, and these were of limited area and had high resistance for microwave current.

The Conference on the Science and Technology of Thin Film Superconductors was conceived in the early part of 1988 as a forum for the specialist in thin film superconductivity. The conference was held on November 14-18, 1988, in Co lorado Springs, Co lorado. Al though many excellent superconductivity conferences had been convened in the wake of the 1986-1987 discoveries in high temperature superconductivity, thin film topics were often dispersed among the sessions of a more general conference agenda. The response to the Conference on the Science and Technology of Thin Film Superconductors confirmed the need for an extended conference devoted to thin film superconductors. These proceedings are a major contribution to the technnology of thin film superconductivity because of the breadth and quality of the articles provided by leaders in the field. The proceedings are divided into articles on laser deposition, sputtering, evaporation, metal organic chemical vapor deposition, thick film, substrate studies, characterization, patterning and applications, and general properties. Most of the articles discuss scientific issues for high temperature thin film superconductors, although the conference was to be a forum for technology and scientific questions for both low and high temperature superconductivity. For the first day of the 5 day conference, Lawrence Berkeley Laboratory had organized an excellent set of short courses in superconduc t ing thin film devices.

There is considerable interest in the intrinsically multiscale structure and dynamics of complex electronic oxides, especially since these materials include those of technological importance, such as colossal magnetoresistance manganites and cuprate high temperature superconductors. Current microscopies, such as diffuse X-ray and inelastic neutron scattering, electromagnetic and acoustic response, NMR and scanning tunneling microscope probes, have revealed static and dynamic multiscale patterns in charge positioning, lattice structure and magnetic orientation, that respond to both external stress and magnetic field. These self-organized patterns include charge and orbital ordering; stripes in strain/spin; and labyrinth-like conductance modulations. The materials exhibit nanoscale phase segregation and mesoscale inhomogeneous clustering, and their phase transitions can have a percolative character.This volume presents experimental and theoretical work on these exciting new developments in condensed matter physics and materials science.

Physical Phenomena at High Magnetic Fields IV (PPHMF-IV) was the fourth in the series of conferences sponsored by the National High Magnetic Field Laboratory (NHMFL). The success of PPHMF-I, II and III, held in 1991, 1995 and 1998 respectively, encouraged the organizers to once again bring together experts in scientific research areas where high magnetic fields play an important role, to critically assess the current status of research in these areas, and to discuss promising new directions in science, as well as applications which are in the forefront of these fields.

The great breakthroughs in the science and technology of superconducting and magnetic materials in recent years promoted many outstanding representatives of various scientific disciplines (physics, chemistry and materials science) to present their latest findings in a scientific atmosphere of the highest standard at the MSM-99 conference. Over 200 eminent scientists from 50 countries gathered to discuss the physics, materials science and application of magnetic and superconducting materials, and to foster research and development collaborations between the scientists and technologists of the regional countries and also with the international scientific community.The main topics of this book are the physics, materials science and application of magnetic and superconducting materials having a close relationship between the strong correlated electron system and magnetism.

This symposium focused on new superconductors, electronics, magnet technology, energy and new applications. Recent discoveries in HTc, with transition temperatures over 90 K, have spawned a search for practical new applications. These applications extend from current uses such as that of the medical MRI to future applications, represented by research on new high-temperature materials. They span from microcircuit applications to the proposed SMES and fusion reactor applications.