It is well recognized that many of the properties of polycrystalline materials are determined
to a large extent by the properties of their internal interfaces. In fact, it has been
commonly remarked that the study of the behaviour of polycrystalline materials is often
reduced to the study of the behaviour of their interfaces. Since the properties of interfaces
between crystals must inevitably depend upon their structure, the study of the structure
and properties of interfaces has emerged as a central area in the larger field of the science
and engineering of materials.
The study of interfaces in crystalline materials has undergone explosive growth during
the last few decades due to: (1) the development of new high-resolution techniques for
studying their atomic structures and behaviour and (2) increased modelling capability
resulting from better theory and the rapid rise of powerful computer simulation methods.
Major publications documenting progress in the field have consisted of the proceedings
of frequently held international conferences and symposia and also edited collections of
papers by different authors devoted to various aspects of interfaces. However, no single
integrated text, spanning the field and written in a pedagogical manner, has yet appeared.
The present book is designed to fill this gap. In writing it we have attempted to develop
the subject systematically and to concentrate on basic ideas and principles. Because of
space limitations, no effort has been made to include detailed descriptions of experimental
techniques. Many of these are covered in other texts. Attention is given to all major types
of interfaces (e.g. homophase and heterophase, diffuse and sharp) between the major
types of materials (e.g. metals, ceramics, semiconductors) to the greatest extent possible
within the covers of a single book of reasonable length. Part I is concerned with structure
and begins with the basic geometry and crystallography of interfaces (Chapter 1) and then
proceeds to dislocation models (Chapter 2). The subject of interatomic forces is then
taken up (Chapter 3) in order to set the stage for the description of the actual detailed
atomic structures of interfaces (Chapter 4). Part II is concerned with the thermodynamics
of interfaces. The basic equilibrium thermodynamic formalism is first laid down (Chapter
5) and serves as a basis for discussion of interfacial phases and phase transitions in
Chapter 6. Finally, the equilibrium segregation of solute atoms to interfaces is treated
in Chapter 7. Part III is concerned with basic kinetic phenomena. These include atomic
diffusion at interfaces (Chapter 8) and both the conservative and non-conservative motion
of interfaces (Chapters 9 and 10, respectively). Non-conservative motion includes the
important notion of interfaces as sources or sinks for diffusional fluxes of atoms. Part
IV is devoted to properties and focuses on the electrical and mechanical properties of
interfaces (Chapters 11 and 12, respectively).