The influence of magnetic field on the thermal properties of solids

The response of a solid to an applied magnetic field can be determined several ways: by direct measurements and by calculating it from magnetization and from the heat capacities as functions of temperature and magnetic field. The magnetocaloric properties of various types of solids are reviewed: normal ferromagnets, materials with multiple magnetic transitions, materials which undergo a first-order transition, and superconductors. Recent developments indicate that the application of the magnetocaloric effect for air conditioning, refrigeration (including freezers), gas liquefaction, etc. is a viable technology. Environmental considerations are also discussed.