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.

As optical fiber communication systems have moved out of the laboratory and into commercial use over the past several years, the general field of guided wave and coherent optics has undergone a radical transformation. Research in optical communication has turned heavily towards single-mode technology and, totally new phenomena and applications of the existing technology, outside the communication field, have begun to proliferate. It was for this reason that we decided to organize a NATO Advanced Study Institute assembling the leading workers in this new domain, in order to define the state of the art, and, develop an idea of the new directions the field might take. The lectures and seminars presented at this Advanced Study Institute form the basis for this book. The subjects treated can be roughly grouped as : - New phenomena in optical fibers such as non-linear effects, soliton propagation and polarization conservation. - New applications of fibers, to measurements of rotation pressure, temperature etc ... and medical uses. - Advanced and exploratory work on single-mode fiber communica tion systems including the use of coherent transmission schemes and optical amplification. - Recent developments of optical information treatment based on four-wave mixing. - Integrated optical devices and technologies including bistable devices, parametric oscillators, and optical logic. In addition to these major topics, a number of national reviews and specialized seminars treating new guided wave structures and materials are included. The co-editors admit being rather pleased with the result.

It is now some 15 years since atomic clusters were first produced and investigated in laboratories. Since then, knowledge concerning clusters has enjoyed rapid and sustained growth, and cluster research has become a new branch of science.

Recent innovations in experimental techniques such as molecular and cluster beam epitaxy, supersonic jet expansion, matrix isolation and chemical synthesis are increasingly enabling researchers to produce materials by design and with atomic dimension. These materials constrained by sire, shape, and symmetry range from clusters containing as few as two atoms to nanoscale materials consisting of thousands of atoms. They possess unique structuraI, electronic, magnetic and optical properties that depend strongly on their size and geometry. The availability of these materials raises many fundamental questions as weIl as technological possibilities. From the academic viewpoint, the most pertinent question concerns the evolution of the atomic and electronic structure of the system as it grows from micro clusters to crystals. At what stage, for example, does the cluster look as if it is a fragment of the corresponding crystal. How do electrons forming bonds in micro-clusters transform to bands in solids? How do the size dependent properties change from discrete quantum conditions, as in clusters, to boundary constrained bulk conditions, as in nanoscale materials, to bulk conditions insensitive to boundaries? How do the criteria of classification have to be changed as one goes from one size domain to another? Potential for high technological applications also seem to be endless. Clusters of otherwise non-magnetic materials exhibit magnetic behavior when constrained by size, shape, and dimension. NanoscaIe metal particles exhibit non-linear opticaI properties and increased mechanical strength. SimiIarly, materials made from nanoscale ceramic particIes possess plastic behavior.

Explore the theory and applications of superatomic clusters and cluster assembled materials Superatoms: Principles, Synthesis and Applications delivers an insightful and exciting exploration of an emerging subfield in cluster science, superatomic clusters and cluster assembled materials. The book presents discussions of the fundamentals of superatom chemistry and their application in catalysis, energy, materials science, and biomedical sciences. Readers will discover the foundational significance of superatoms in science and technology and learn how they can serve as the building blocks of tailored materials, promising to usher in a new era in materials science. The book covers topics as varied as the thermal and thermoelectric properties of cluster-based materials and clusters for CO2 activation and conversion, before concluding with an incisive discussion of trends and directions likely to dominate the subject of superatoms in the coming years. Readers will also benefit from the inclusion of: A thorough introduction to the rational design of superatoms using electron-counting rules Explorations of superhalogens, endohedrally doped superatoms and assemblies, and magnetic superatoms A practical discussion of atomically precise synthesis of chemically modified superatoms A concise treatment of superatoms as the building blocks of 2D materials, as well as superatom-based ferroelectrics and cluster-based materials for energy harvesting and storage Perfect for academic researchers and industrial scientists working in cluster science, energy materials, thermoelectrics, 2D materials, and CO2 conversion, Superatoms: Principles, Synthesis and Applications will also earn a place in the libraries of interested professionals in chemistry, physics, materials science, and nanoscience.

Due to the interaction with the contact medium, the properties of clusters may change or even disappear. Thus the physics of cluster-on-surface systems -- the main subject of this book -- is of fundamental importance. The book addresses a wide audience, from the newcomer to the expert. Starting from fundamental concepts of adsorbate-surface interactions, the modification of electronic properties through electron confinement, and concepts of cluster production, it elucidates the distinct properties of the new metallic nanostructures.

纳米相和纳米结构材料是纳米科学和纳米技术的基础,本书集中介绍和阐述了半导体纳米颗粒、半导体纳米线、磁性纳米晶体及其排列、纳米结构的软磁性材料、用于信息存储等纳米材料的应用。