The influence of magnetic field on the thermal properties of solids

The response of a solid to an applied magnetic field can be determined seve ral ways: by direct measurements and by calculating it from magnetization a nd from the heat capacities as functions of temperature and magnetic field. The magnetocaloric properties of various types of solids are reviewed: nor mal ferromagnets, materials with multiple magnetic transitions, materials w hich undergo a first-order transition, and superconductors. Recent developm ents indicate that the application of the magnetocaloric effect for air con ditioning, refrigeration (including freezers), gas liquefaction, etc. is a viable technology. Environmental considerations are also discussed. (C) 200 0 Elsevier Science S.A. All rights reserved.