This is the third book in the new series "Material Research and Engineering," devoted to the science and technology of materials. "MRE" evolves from a previous series on "Reine und Angewandte Metallkunde," which was edited by Werner Koster until his eightieth birthday in 1976. For the new series, the presentation as well as the scope had to be modified. In particular, the scientific and technological links between volumes on metallic, non-metallic, and composite materials should reflect the successful development of materials science and engineering within the last two decades. Thus, the material provided by Dorre and Hlibner for the present volume is partic ularly welcome. Alumina as a ceramic material has received very large attention as an object of scientific investigation in all of its aspects. Additionally, it plays a leading role as a nonmetallic material in many fields of technical appli cation. This book deals with both aspects: in Chapter 2 (physical properties) and 3 (me chanical properties), H. Hlibner presents an outstanding documentation of what one might call the science of alumina, based on 560 literature references and 15 years of personal experience gained from experimental and theoretical work in university laboratories in Erlangen, Rio de Janeiro, and Hamburg. In Chapter 4 (fabrication) and 5 (applications), E."

The Institut Max von Laue-Paul Langevin (ILL) in Grenoble regularly orga nizes workshops that deal with various applications of neutrons in physics, chemistry, biology and materials science. The workshop "Quantum Aspects of Molecular Motions in Solids" was jointly organized by the Institut Laue Langevin and the Institut fiir Festkorperforschung at the Kernforschungsan lage Jiilich and took place in September 1986 in Grenoble. Tunneling phenomena in molecular crystals were first observed with macro scopic methods like specific heat experiments and later also with NMR. Fi nally, the development of high resolution neutron scattering techniques like neutron backscattering led to direct spectroscopic observation of the tunnel split ground state. This breakthrough was achieved in 1975 at Jiilich. Since then the large variety of high-resolution techniques available in combination with high neutron flux have turned ILL into the leading laboratory in the field of tunneling spectroscopy. Since 1980 regular meetings of scientists involved in this topic have been organized every two years (Jiilich, Braunschweig, Nottingham) and have led to an intense exchange of ideas and experimental results. The present workshop is the fourth of this series and the first with published proceedings presenting the state of the art in this field. The eight review articles introduce scientists not involved in the subject to the actual discussion. Sessions on translational tunneling of light interstitials in metals as well as on tunneling phenomena in amorphous substances provide bridges to adjacent fields."

During the past thirty years considerable efforts have been made to design the synthesis and the study of molecular semiconductors. Molecular semiconductors - and more generally molecular materials - involve interactions between individual subunits which can be separately synthesized. Organic and metallo-organic derivatives are the basis of most of the molecular materials. A survey of the literature on molecular semiconductors leaves one rather confused. It does seem to be very difficult to correlate the molecular structure of these semiconductors with their experimental electrical properties. For inorganic materials a simple definition delimits a fairly homogeneous family. If an inorganic material has a conductivity intermediate between that of an 12 1 1 3 1 1 insulator " 10- n- cm- ) and that of a metal (> 10 n- cm- ), then it is a semiconductor and will exhibit the characteristic properties of this family, such as junction formation, photoconductivity, and the photovoltaic effect. For molecular compounds, such simplicity is certainly not the case. A huge number of molecular and macromolecular systems have been described which possess an intermediate conductivity. However, the various attempts which have been made to rationalize their properties have, more often than not, failed. Even very basic electrical properties such as the mechanism of the charge carrier formation or the nature and the density ofthe dopants are not known in detail. The study of molecular semiconductor junctions is very probably the most powerful approach to shed light on these problems.

This volume is based on lectures and contributed papers presented at the Eleventh Course of the International School of Materials Science and Tech nology that was held in Erice, Sicily, Italy at the Ettore Majorana Center for Scientific Culture during the period 6-17 July 1986. The subject of the course was "Electro-optic and Photorefractive Materials: Applications in Sig nal Processing and Phase Conjugation" . The fields of electro-optics and photorefraction have developed rapidly since the invention of lasers just over twenty-five years ago. The possibil of altering the optical properties of a material by electric fields or by ity optical waves is of great importance for both pure science and for practical applications such as optical signal processing, telecommunications and opti cal display devices. These effects allow us to manipulate (modulate, deflect) and process a given light wave. Modulation, deflection and processing of light waves by means of the electro-optic effect is of fundamental importance in fiber optic telecommuniC1. tions and sensor systems w here the light signals can be processed prior or subsequent to transmission through the fibers. Thin film electro-optic materials with suitable electrode arrays on. the surface of the wave-guiding structures result in a technology often referred to as inte grated optics. In principle, integrated optics devices allow miniaturization and integration of many operations onto a single chip. The photorefractive effect, defined as a photo-induced change of the in dices of refraction, was the other topic treated in this course."

In 1987 a major breakthrough occurred in materials science. A new family of materials was discovered that became superconducting above the temperature at which nitrogen gas liquifies, namely, 77 K or -196 DegreesC. Within months of the discovery, a wide variety of experimental techniques were brought to bear in order to measure the properties of these materials and to gain an understanding of why they superconduct at such high temperatures. Among the techniques used were electromagnetic absorption in both the normal and the superconducting states. The measurements enabled the determination of a wide variety of properties, and in some instances led to the observation of new effects not seen by other measu- ments, such as the existence of weak-link microwave absorption at low dc magnetic fields. The number of different properties and the degree of detail that can be obtained from magnetic field- and temperature-dependent studies of electromagnetic abso- tion are not widely appreciated. For example, these measurements can provide information on the band gap, critical fields, the H-T irreversibility line, the amount of trapped flux, and even information about the symmetry of the wave function of the Cooper pairs. It is possible to use low dc magnetic field-induced absorption of microwaves with derivative detection to verify the presence of superconductivity in a matter of minutes, and the measurements are often more straightforward than others. For example, they do not require the physical contact with the sample that is necessary when using four-probe resistivity to detect superconductivity.

This volume contains the talks presented at the International Symposium on Electronic Excitations and Interaction Processes in Organic Molecular Aggre gates which was held at Schloss Elmau, Bavaria, Germany from June 5 to June 10, 1983. In the recent years the investigation of organic materials has developed rapidly and has led to the construction of materials with interesting proper ties. The discovery of highly conducting and superconducting organic materials is definitely one of the reasons for the enormous increase in research acti vity in this field. Interesting applications have been realized or seem pos sible, such as the application of organic materials in electrophotography. The conductivity of organic polymers may be varied within a large range by doping and such materials have been used to construct an organic battery. Some time ago it was suggested that organic glasses and polymers could be used as stor age materials in computer technology. With the development of preparation tech niques and modern methods of investigation, for example, high resolution and picosecond spectroscopy, a large amount of experimental data is available not only for the conducting materials but also for organic semiconductors and in sulators. With this rapid accumulation of experimental material the microscopic theoretical understanding could not keep pace."

The growth and maturity of research in structural phase transitions (SPT) make it an appropriate subject for the Topics in Current Physics series. The maturing pro- cess is, however, by no means complete. New areas such as incommensurable SPT, quasi-low-dimensional systems, systems containing lattice disorder due to impuri- ties or as mixed crystals, multicritical points, and quantum effects have recently come under focus. The understanding of the dynamics, be it microscopic soft-mode theory or critical dynamics, more specifically the central-peak problem, is also still quite incomplete. On the other hand, there are areas which are genuinely conso 1 ida ted. On the theoreti ca 1 s ide~ these concern symmetry properti es, Landau theory, and the application of static renormalization theory to critical phenomena. ,Also, the use of various complementary experimental techniques, with their specific merits, are well in hand. The field of STP's and of the various methods of investigation range so widely that it appeared appropriate to invite a number of scientists to review their respective areas of experti se to which they have made s i gnifi cant contri butions.

This book contains the invited review papers and contributed papers presented at the University of Tokyo International Symposium on Anderson localization. It provides an overview of rapidly developing topics related to this area, including the metal-insulator transition in doped semiconductors and disordered metals, weak localization phenomena in two- and three-dimensional dirty metals and semiconductor space-charge layers, the quantum Hall effect, and localization in strong magnetic fields, together with the newer subjects of quasicrystals and mesoscopic systems. Quasicrystals are particularly interesting because their wave functions exhibit self-similarity and are marginally localized or delocalized, while in mesoscopic systems the conductance is no longer a self-averaged quantity and fluctuations play an essential role. This volume should be of use to anyone interested in the development of Anderson localization.

Describes the main aspects of chirality in liquid crystals, and points out some of the open questions of current research. The chapters review the highlights of the important topics and questions.

Discovery of new transport phenomena and invention of electron devices through exploitation of these phenomena have caused a great deal of interest in the properties of compound semiconductors in recent years. Extensive re search has been devoted to the accumulation of experimental results, par ticularly about the artificially synthesised compounds. Significant ad vances have also been made in the improvement of the related theory so that the values of the various transport coefficients may be calculated with suf ficient accuracy by taking into account all the complexities of energy band structure and electron scattering mechanisms. Knowledge about these deve lopments may, however, be gathered only from original research contributions, scattered in scientific journals and conference proceedings. Review articles have been published from time to time, but they deal with one particular material or a particular phenomenon and are written at an advanced level. Available text books on semiconductor physics, do not cover the subject in any detail since many of them were written decades ago. There is, there fore, a definite need for a book, giving a comprehensive account of electron transport in compound semiconductors and covering the introductory material as well as the current work. The present book is an attempt to fill this gap in the literature. The first chapter briefly reviews the history of the developement of compound semiconductors and their applications. It is also an introduction to the contents of the book."

This volume summarizes the papers presented at the First Osaka University Macromolecular Symposium OUMS'93 on "Ordering in Macromolecular Systems," which was held at Senri Life Science Center, Osaka, Japan, on June 3 through June 6, 1993. The symposium covered the three topics, (1) Crystallization and Phase Transitions, (2) Polymer Liquid Crystals and (3) Block Copolymers, Polymer Blends and Surfaces, and invited leading scientists in these fields. At present any of these topics is a hot issue in itself and frequently taken up separately in many occasions. It is noted however that all these topics are correlated with each other with the keyword "Ordering" and their combination provides a unique feature of the present symposium in reflecting the interactions among investigators working in these important fields with the common ground expressed by the keyword "Ordering." Nineteen invited lectures and 40 posters of both experiment and theory were presented at the symposium, and the eighteen lectures and ten poster presentations contribute to this volume. In the first topic crystal structures and their transitions were discussed from kinetic as well as static points of view; attention was paid to give a molecular-level interpretation of the structure, phase transition and physical properties, using theories and simulations. The second topic was mainly concerned with static structures and thermodynamic properties of polymer liquid crystals including phase behaviours.

Correlation Effects in Low-Dimensional Electron Systems describes recent developments in theoretical condensed-matter physics, emphasizing exact solutions in one dimension including conformal-field theoretical approaches, the application of quantum groups, and numerical diagonalization techniques. Various key properties are presented for two-dimensional, highly correlated electron systems.

In the last two decades low-dimensional (low-d) physics has matured into a major branch of science. Quite generally we may define a system with restricted dimensionality d as an object that is infinite only in one or two spatial directions (d = 1 and 2). Such a definition comprises isolated single chains or layers, but also fibres and thin layers (films) of varying but finite thickness. Clearly, a multitude of physical phenomena, notably in solid state physics, fall into these categories. As examples, we may mention: * Magnetic chains or layers (thin-film technology). * Metallic films (homogeneous or heterogeneous, crystalline, amorphous or microcristalline, etc.). * I-d or 2-d conductors and superconductors. * Intercalated systems. * 2-d electron gases (electrons on helium, semiconductor interfaces). * Surface layer problems (2-d melting of monolayers of noble gases on a substrate, surface problems in general). * Superfluid films of ~He or 'He. * Polymer physics. * Organic and inorganic chain conductors, superionic conductors. * I-d or 2-d molecular crystals and liquid crystals. * I-d or 2-d ferro- and antiferro electrics.

The International Symposium on Dynamics of Ordering Processes in Condensed Matter was held at the Kansai Seminar House, Kyoto, for four days, from 27 to 30 August 1987, under the auspices of the Physical Soci ety of Japan. The symposium was financially supported by the four orga nizations and 45 companies listed on other pages in this volume. We are very grateful to all of them and particularly to the greatest sponsor, the Commemorative Association for the Japan World Exposition 1970. A total Df 22 invited lectures and 48 poster presentations were given and 110 participants attended from seven nations. An objective of the Symposium was to review and extend our present understanding of the dynamics of ordering processes in condensed matters, (for example, alloys, polymers and fluids), that are brought to an un stable state by sudden change of such external parameters as temperature and pressure. A second objective, no less important, was to identify new fields of science that might be investigated by similar, but sometimes more sophisticated, concepts and tactics. An emphasis was laid on those universal aspects of the laws governing the ordering processes which transcended the detailed differences among the substances used. The 71 lectures reproduced in this volume bear witness to the success of the Symposium in meeting amply the first objective and, to a lesser extent, the second."

In interaction the between the leads to a quantum liquids particles variety of and unusual states of condensed matter interesting systems, super e.g. and the fractional in electron Hall effect conductivity quantum (FQHE) sys tems. In this book for we investigate quantum field theoretical approaches fermion the is interacting systems. Originally, quantum fieldtheory designed describe as a to perturbation theory weakly interacting many particle sys tems. For treatment of interaction and correlation effects a proper beyond the the series of must beresummed perturbation theory, Feynmandiagrams severalresummationschemeswhich the We on partially. present depend par ticular effect considered.We start with ofthe a physical compactdescription self consistent and the quantum fieldtheory approximations. conserving the of in fermion is caused two Superconductivity systems by interplay formation ofbound attractive interaction between the phenomena: pairsby fermions condensation ofthe low to and at temperatures leading long pairs order and We consider three dimensional of a range superfluidity. system fermionswith attractiveinteractionwhichshowsacrossoverfrom short range BCS to Bose Einstein condensation ofbound ifthe superconductivity pairs interaction is tuned fromweak to While the self coupling. strength strong consistent version ofthe is well suited to describe con quantum field theory densation of and a second resummation to the pairs superfluidity, leading the ofbound Bethe Salpeter equation describes formation pairs.

191 Apart from numerous difficulties arising from the high pressure technique as such, there is a natural limitation to the possibility of applying a hydrostatic pressure, since liquids under pressure will solidify above a certain pressure limit. 8 2 Up to pressures of 3 X 10 kg.jm. at room temperature, a liquid like isopentane can be used. For higher pressures helium gas may be used, perhaps to about 9 2 10 kg.jm. , but BRIDGMAN already encountered enormous leakage difficulties 7 when using this gas at 7.10 kg.jm.2 at 90 Degrees K. A solution has been found by applying mechanical pressure for the range 8 9 2 between 3 X 10 and 10 kg.jm. , by using silver chloride as transmittant. In this case, however, one has to apply unknown corrections for shearing stress and deformation of the sample, a problem which BRIDGMAN solved experimentally by a determination of the resistivity in the pressure region between 2 and 8 2 5 X 10 kg.jm. , by the hydrostatic and by the mechanical pressure method as well, and applying the correction factor thus determined to the results obtained at higher pressures. Though this method seems to be right in good approximation, the data for the highest pressures are to be considered as less accurate.

Optical data storage represents a major chapter in the history of information storage and the invention of rewritable media has indisputably been an essential addition to the optical storage family. With the multiple overwrite feature, rewritable optical discs have found application in consumer DVD+RW video recorders, professional archiving systems and computer drives for data storage, replacing the floppy disc in the latter case.

Optical Data Storage provides an overview of the recording principles, materials aspects, and application areas of phase-change optical storage. Some theoretical background is given to familiarize the reader with the basics of the phase-change processes. Elements of data recording, including mark formation, eraseability, direct overwrite strategies, data quality and data stability, etc are explained and extensively discussed. A mark formation model is described and used throughout the whole book to back-up measurement results and support the discussed applications. Two major aspects high-speed and dual-layer recording are considered in depth and solutions to achieve higher performance are analyzed.

Optical Data Storage is aimed at a broad range of readers from university teams studying the subject to industrial media manufacturers requiring insights into performance of rewritable optical media."

The nitrides and carbides of boron and silicon are proving to be an excellent choice when selecting materials for the design of devices that are to be employed under particularly demanding environmental and thermal con- tions. The high degree of cross-linking, due to the preferred coordination numbers of the predominantly covalently bonded constituents equalling or exceeding three, lends these non-oxidic ceramics a high kinetic stability, and is regarded as the microscopic origin of their impressive thermal and mechanical durability. Thus it does not come as a surprise that the chemistry, the physical properties and the engineering of the corresponding binary, ternary, and even quaternary compounds have been the subject of intensive and sustained efforts in research and development. In the five reviews presented in the volumes 101 and 102 of "Structure and Bonding" an attempt has been made to cover both the essential and the most recent advances achieved in this particular field of materials research. The scope of the individual contributions is such as to address both graduate students, specializing in ceramic materials, and all scientists in academia or industry dealing with materials research and development. Each review provides, in its introductory part, the chemical, physical and, to some extent, historical background of the respective material, and then focuses on the most relevant and the most recent achievements.

Although it has long been possible to make organic materials emit light, it has only recently become possible to do so at the level and with the efficiency and control necessary to make the materials a useful basis for illumination in any but the most specialized uses. This book surveys the current status of the field.

One of the main goals of investigations of shock-wave phenomena in condensed matter is to develop methods for predicting effects of explosions, high-velocity collisions, and other kinds of intense dynamic loading of materials and structures. Based on the results of international research conducted over the past 30 years, this book is addressed not only to experts in shock-wave physics, but also to interested representatives from adjacent fields of activity and to students who seek an introduction to the current issues. With that goal in mind, the book opens with a brief account of the theoretical background and a short description of experimental techniques. The authors then progress to a systematic treatment of special topics, some of which have not been fully addressed in the literature to date.

Ordered systems exhibit physical properties and behavior unknown in media where structural ordering and organization do not take place. In ordered systems special correlations between molecules exist and the results are remarkable properties: the functional order of biological systems, the electrooptical and mechanical proper ties of liquid crystalline materials and stretched polymers are just a few examples. New methods and techniques in optical spectroscopy have recently been developed to study ordered systems and guest molecules. This stimulated the organization of a NATO Advanced Study Institute bringing together chemists and physicists from optical spectroscopy, materials science, and biology. Thereby a unifying and interdisciplinary survey of possible applications of spectroscopy with polarized light to ordered systems, such as liquid crystals, stretched polymers, polymeric liquid crystals, and membranes, was achieved. The interdisciplinary approach of the meeting is reflected in the book. Different aspects of the same topic are often treated in several chapters all through the book. Therefore, each reader should look for the contributions which serves his needs, even if this means that some chapters will be skipped. The Advanced Study Institute, "New Developments in Polarized Spectroscopy of Ordered Systems," was the first scientific event of the celebrations of the 900th anniversary of the University of Bologna. The international and multidisciplinary approach of this ASI well converged in the tradition of the "Studium" at Bologna."

During the last decade there has been an increasing interest in clusters and small particles because of the peculiar proper ties induced by their large area to volume ratio. For that reason small particles are often considered as an intermediate state of matter at the border between atomic (or molecular) chemistry, and physics of the condensed matter. The importance of the surface effect can explain the anomalous properties, for example the exis tence of the five fold symmetry observed in different circumstan ces '(beams of rare gas clusters, gold particles deposited on a substrate). However the question of the critical size at which the transition to bulk properties occurs cannot be simply answered, since the reply depends on the peculiar property which is studied. The importance of the size effect was emphasized in the last International Meetings. However the situation remains confused in most cases since the exact role of the cluster environment cannot be clearly elucidated and is a main difficulty, except in cluster beam experiments. In fact ideally free clusters constitute a labo ratory exception. In most applications small particles must be supported on a surface or embedded in a matrix, in order to be stabilized, which obviously shows the role of the environment."

The Institut Max-von-Laue-Paul Langevin (ILL) in Grenoble regularly organ ises workshops that deal with the various applications of neutrons in physics, chemistry, biology and also in nuclear physics. The workshop" Atomic Trans port and Defects in Metals by Neutron Scattering," jointly organised by the Institut Laue-Langevin and the Institut fiir Festkorperforschung of the KFA Jiilich, was held in October 1985 in Jiilich. The study of problems in metal physics and in physical metallurgy is a traditional field of neutron scattering. The most commonly used methods are diffuse elastic, small-angle and inelastic scattering of neutrons. A number of problems can be identified where neutrons yield information that is supple mentary to that from other methods such as x-ray diffraction, synchrotron radiation or electron microscopy. In certain fields, for example spectroscopy for the investigation of atomic motions or for the investigation of magnetic properties, neutron scattering is a unique method. The facilities at the High Flux Reactor of the ILL, and also at the Jiilich and at other medium flux research reactors, have contributed numerous re sults in these fields. It was the aim of this workshop to give a survey of the present state of neutron scattering in metal physics."

In recent decades surface science has experienced a large growth in connection with the development of various experimental techniques which are able to characterize solid surfaces through the observation of the scattering of ions, electrons, photons or atoms. These methods of investigation, known under different labels such as LEED, AES, XPS, UPS, etc. have been extensively applied in describing the structure, morphology, and chemical and physical properties of crystal surfaces and interfaces of a large variety of materials of interest in solid-state physics, electronics, metallurgy, biophysics, and heterogeneous catalysis. Among these methods we wish to emphasize molecular beam scattering from solid surfaces. ~lolecular beam scattering has gone through a large development in the last ten years. In this decade a large number of laboratories have used this method to study various clean and adsorbate-covered surfaces. The technique is nonetheless quite old. It dates back to the beginning of the thirties, when Estermann and Stern performed the first atom diffraction experiment proving the wave nature of atoms. In the following years the entire subject of gas-surface interaction was considered a branch of rarefied gas dynamics and developed in connection with aerospace research. Attention was then given to the integral properties of gas-solid interactions (sticking and energy accomodation, mean momentum transfer) rather than to atom-surface scatter ing from well-characterized surfaces.

Both experimental and theoretical investigations make it clear that mesoscale materials, that is, materials at scales intermediate between atomic and bulk matter, do not always behave in ways predicted by conventional theories of shock compression. At these scales, shock waves interact with local material properties and microstructure to produce a hierarchy of dissipative structures such as inelastic deformation fields, randomly distributed lattice defects, and residual stresses. A macroscopically steady planar shock wave is neither plane nor steady at the mesoscale. The chapters in this book examine the assumptions underlying our understanding of shock phenomena and present new measurements, calculations, and theories that challenge these assumptions. They address such questions as: - What are the experimental data on mesoscale effects of shocks, and what are the implications? - Can one formulate new mesoscale theories of shock dynamics? - How would new mesoscale theories affect our understanding of shock-induced phase transitions or fracture? - What new computational models will be needed for investigating mesoscale shocks?