Springer Series in Cluster Physics – serie

Clusters and nanoscale materials give rise to properties and behaviour that are governed by size restrictions, and hence display features directly attributable to quantum confinement. Thus they represent ideal media for observing and studying quantum phenomena. This book presents and evaluates some of the latest developments in this area of basic research. Each of the chapters focuses on selected aspects of the field, and the authors endeavour to display the breadth of the subject by presenting some of the important recent advances that have been made through the use of new experimental techniques and theoretical approaches.

The evolution of the physical/ chemical sciences towards understanding the behavior of matter at the molecular level has been accompanied by a rapid increase in studies of the properties and functioning of confined water; that is, water in small clusters and nanoparticles or confined to solid/liquid thin films, surfaces and interfaces. These studies represent a convergence of interests and methodologies. That is, much emerging science, both basic and applied, depends on an understanding of confined water for significant advances; and the technical ability to gain that understanding has evolved only during the past decade or two. Firm concepts of the behavior of water in a variety of confining geometries are basic to advances in molecular biology, weather phenomena, atmospheric chemistry, interstellar and interplanetary physics and chemistry; as weIl as to the complete understanding of properties of macroscopic amounts of water and water-solute systems. In recognition of the growing importance of studies of confined water, a Telluride (Colorado) workshop was convened in August of 2000. This was an exceptionally strong 5-day conference with numerous informative talks by leading scientists on both basic and applied aspects of the subject. Lively discussions left the participants spent.

The field of cluster sciences is currently attracting considerable interest, not only from a fundamental viewpoint but also in relation to future applications to electronic, optical and magnetic devices. Synthesizing specific clusters as a component of useful nanostructures or controlling them as an assembly of nanocomposites is the ultimate aim. In order to understand how to synthesize individual clusters or to investigate properties such as chemical reaction, structural stability, response to external fields, aggregation and phase transitions, a variety of first-principles and empirical calculations and related computer simulations have been performed alongside numerous experiments. This book compiles and collates recent theoretical and experimental advances in the field and demonstrates how the harmony between theory and experiment is contributing to the continuing rapid progress. It will be of interest to both researchers as well as students and newcomers seeking an up-to-date review.

Numerous experiments and calculations have shown that isolated metal clusters possess many interesting features, quite different from those known from surface and solid- state physics or from atomic and molecular physics. The technological exploitation of these new properties, e.g. in miniature electronic or mechanical components, requires the cluster to be brought into an environment such as an encapsulating matrix or a surface. Due to the interaction with the contact medium, the properties of the 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.

Clusters and nanoscale materials give rise to properties and behaviour that are governed by size restrictions, and hence display features directly attributable to quantum confinement. Thus they represent ideal media for observing and studying quantum phenomena. This book presents and evaluates some of the latest developments in this area of basic research. Each of the chapters focuses on selected aspects of the field, and the authors endeavour to display the breadth of the subject by presenting some of the important recent advances that have been made through the use of new experimental techniques and theoretical approaches.

The evolution of the physical/ chemical sciences towards understanding the behavior of matter at the molecular level has been accompanied by a rapid increase in studies of the properties and functioning of confined water; that is, water in small clusters and nanoparticles or confined to solid/liquid thin films, surfaces and interfaces. These studies represent a convergence of interests and methodologies. That is, much emerging science, both basic and applied, depends on an understanding of confined water for significant advances; and the technical ability to gain that understanding has evolved only during the past decade or two. Firm concepts of the behavior of water in a variety of confining geometries are basic to advances in molecular biology, weather phenomena, atmospheric chemistry, interstellar and interplanetary physics and chemistry; as weIl as to the complete understanding of properties of macroscopic amounts of water and water-solute systems. In recognition of the growing importance of studies of confined water, a Telluride (Colorado) workshop was convened in August of 2000. This was an exceptionally strong 5-day conference with numerous informative talks by leading scientists on both basic and applied aspects of the subject. Lively discussions left the participants spent.

The field of cluster science is currently attracting considerable interest, not only from a fundamental standpoint, but also through its future applications to electronic, optical, magnetic, and other devices. Synthesizing specific clus­ ters as a unit of useful nanostructures or controlling them as an assembly of nanocomposites is one of the ultimate purposes in this field. In order to understand how to synthesize individual clusters and t_o investigate physical properties, chemical reactions, structural stability, response to external fields, aggregation, phase transition, and other aspects of clusters, a great deal of effort has gone into experiment, theory and computer simulation in this area. This is presumably motivated by the fact that a high level of collaboration between theoretical and experimental researchers is particularly important for progress in the field of cluster science. The present book aims to collect together recent advances in this rapidly growing field. The authors are all active researchers, collaborating both ex­ perimentally and theoretically in this field, and most of them have regularly participated in the IMR Workshop, held for three years starting from 1998 at the Institute for Materials Research in Tohoku University. This book is suitable for both theoretical and experimental researchers and also for re­ searchers and graduate students working in related subjects, who wish to overview recent advances in the field.

Numerous experiments and calculations have shown that isolated metal clusters possess many interesting features, quite different from those known from surface and solid- state physics or from atomic and molecular physics. The technological exploitation of these new properties, e.g. in miniature electronic or mechanical components, requires the cluster to be brought into an environment such as an encapsulating matrix or a surface. Due to the interaction with the contact medium, the properties of the 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.

The emergence and spectacularly rapid evolution of the field of atomic and molecular clusters are among the most exciting developments in the recent his- tory of natural sciences. The field of clusters expands into the traditional disci- plines of physics, chemistry, materials science, and biology, yet in many respects it forms a cognition areaofits own. The identifying attributes ofthis area reflect the specificity ofthe objects, subjects, problems, and issues it addresses, and the concepts, methodologies, techniques, and tools it utilizes. All these ultimately relate to and are defined by a single common characteristic - the finite size of the targeted systems. Theterm "finite" represents a broad rangeofsizes- from small (afew to a few tens of atoms and molecules) to large (thousands of atoms and molecules). This varietyof si~es and thesize-dependenceofthe propertieswould alone besufficient to make the cluster field a broad and challenging research area. The variety of elements one can use (and nature uses) to form clusters and the different types of interatomic interactions in clusters of different elements and materials only enhance the diversity and the richness of the field.To unravel, understand, and describe cluster properties one often has to in- voke complementaryconcepts and techniques, and, what is most challenging and stimulating, develop new ones. This book presents a "cross section" of theoreti- cal approaches and their applications in studies ofdifferent cluster systems. The last three articles provide a "glimpse" at experimental cluster research.

This book supplies a systematic description of the preparation, characterization, and manipulation of cluster beams for the synthesis of nanocrystalline materials. It addresses all issues relevant to the realization of nanophase structures, providing an excellent introduction for scientists working in different fields. Particular emphasis is placed on using the technique for nanostructured materials and on explaining the role of cluster beams within the context of other experimental techniques in surface-science.