Theory of Symmetry Changes at Continuous Phase Transitions (Phase transition phenomena)

Since Landau formulated the first theory of symmetry changes at continuous phase transitions, a number of authors have proposed other methods for solving the problem or have introduced important modifications to the original theory. In spite of the growing interest in phase transition phenomena, no book has yet dealt exclusively with the subject of symmetry changes. The present work covers the various approaches to the theory of symmetry changes and provides examples of applications of these methods. Details of group-theoretical calculations are given. The book may therefore interest research workers, and postgraduate and undergraduate students specializing in solid state theory. The book contains: (1) Landau's theory of symmetry changes with examples of its application to magnetic and non-magnetic crystals; (2) other theories of symmetry changes with examples and applications; (3) an introduction to the theory of symmetry changes in liquid crystals and to the theory of symmetry of critical fluctuations; (4) an exposition of group-theoretical principles and formulae which are applied in the calculations of symmetry changes. The emphasis is given to explaining the mathematical methods of investigation and to demonstrating the consecutive steps in the calculations. A knowledge of the basic theory of representations of finite groups and some familiarity with space-group concepts are necessary for understanding the text.