This textbook describes the fundamental principles of structural phase transitions in materials in an easily understandable form, suitable for both undergraduate and graduate students. Ferroelasticity, twinning and related microstructures are described. Landau-type theories of phase transitions are introduced, together with details of elastic and specific heat anomalies, the formation of spontaneous strain, and the generation of solitary waves at temperatures close to the transition point. Many materials used in industry are crystals. These crystals often show anomalies such as sudden softening or embrittlement at certain temperatures; if controlled, such behaviour can be extremely useful for manufacturing and high technology applications. This is one of the first books to describe the recently determined physical origins of such behaviour, and provides an insight into the important thermodynamic principles and microstructural properties involved.

"...the author is admired for integrating the subject at its infancy; the book describes phenomena, domain structures, and theories of phase transition and wall mobility, with generous illustrations of geologically interesting materials. The first few chapters are suitable for general reading, the level being similar to the articles in Scientific American. The more persistent readers will benefit from later chapters and a long bibliography of known co-elastic crystals. I strongly recommend this book to all science and engineering libraries, as well as to anyone who wishes to learn ferroelasticity." Z. Suo, PAGEOPH