The present volume contains the courses given at a Summer School on "Magne tic Phase Transitions" held at the Ettore Majorana Centre for Scientific Culture, at Erice (Trapani), Italy in July 1983 under the auspices of the Condensed Matter Division of the European Physical Society in their series on Materials Science and Technology. The student participants came from West Germany, Great Britain, Brazil, Greece, Switzerland, Sweden, Italy, USA and The Netherlands. The lecturers came from various European countries, Israel, USA and Canada. The atmosphere at the meeting was excellent and a good...