Physics Of Amorphous Materials

This book was written to be an introduction to the science of amorphous materials. It is aimed at final year undergraduates, beginning graduate students and researchers in solid-state physics or chemistry, materials science or engineering.

An in-depth study of non-crystalline solids in which the arrangement of the atoms do not have long-range order. Describes the way amorphous solids are formed, the phenomenology of the liquid-to-glass and glass- to-liquid transition, and the technological applications. Emphasizes modern approaches such as scaling, localization, and percolation. Includes extensive treatment of structural aspects of amorphous solids, ranging from metallic glasses, to chalcogenides, to organic polymers. Incorporates illustrations for the clarification of physics concepts.

The aim of this NATO ASI has been to present an up-to-date overview of current areas of interest in amorphous materials, with particular emphasis on electronic properties and device applications. In order to limit the material to a manageable amount, the meeting was concerned almost exclusively with semiconducting materials. This volume should be regarded as a follow-on to the NATO ASI held in Sozopol, Bulgaria in 1996 and published as "Amorphous Insulators and Semiconductors" edited by M.F. Thorpe and M.1. Mitkova (Kluwer Academic Publishers, NATO ASI series, 3 High Technology - Vol. 23). The lectures and seminars fill the gap between graduate courses and research seminars. The lecturers and seminar speakers were chosen as experts in their respective areas, and the lectures and seminars that were given are presented in this volume. During the first week of the meeting, an emphasis was placed on introductory lectures while the second week focused more on research seminars. There were two very good poster sessions that generated a lot of discussion, but these are not reproduced in this volume as the editors wanted to have only larger contributions to make the proceedings more coherent.

Structurally disordered solids are characterized by their lack of spatial order that is evidenced by the great variety of ordered solids. The former class of materials is commonly termed amorphous or glassy, the latter crystalline. However, both classes share, many of the other physical properties of solids, e. g. , me chanical stability, resistance to shear stress, etc. The traditional macroscopic distinction between the crystalline and the glassy states is that while the former has a fixed melting point, the latter does not. However, with the availability and production of a large number of materials in both crystalline and amorphous states, and their easy inter-convertability, simple de finitions are not possible or at best imprecise. For the present purpose, it is sufficient to say that in contrast to the crystalline state, in which the posi tions of atoms are fixed into adefinite structure, ex cept for small thermal vibrations, the amorphous state of the same material displays varying degrees of de parture from this fixed structure. The amorphous state almost always shows no long range order. Short range order, up to several neighbors, may often be retained, although averaged considerably around their crystalline values. It is generally believed that the amorphous state is a metastable one with respect to the crystal line ordered state, and the conversion to the crystal line state may or may not be easy depending on the na ture of the material, e. g.

This review addresses the current state-of-the-art in the physics of amorphous materials and its practical applications. Because of the keen interest in these new technological innovations in the amorphous material application fields, particular emphasis has been placed on some important basic knowledge and current topics in the application fields which inlude information directly useful to scientists and R&D engineers in industry, institutes and university laboratories.

The Institute for Amorphous Studies was founded in 1982 as the international center for the investigation of amorphous mate rials. It has since played an important role in promoting the und er standing of disordered matter in general. An Institute lecture series on "Fundamentals of Amorphous Materials and Devices" was held during 1982-83 with distinguished speakers from universities and industry. These events were free and open to the public ,and were attended by many representatives of the scientific community. The lectures themselves were highly successful inasmuch as they provided not only formal instruction but also an opportunity for vigorous and stimulating debate. That last element could not be captured within the pages of a book I but the lectures concentrated on the latest advances in the field I which is why their essential contents are he re reproduced in collective form. Together they constitute an interdisciplinary status report of the field. The speakers brought many different viewpoints and a variety of back ground experiences io bear on the problems involved I but though language and conventions vary I the essential unity of the concerns is very clear I as indeed are the ultimate benefits of the many-sided approach.