Magnetocaloric effect in thin magnetic films γ-Fe2O3
Аннотация
Abstract In this paper, we studied the thermal properties of thin films associated with significant difficulties caused by their small volume. Nevertheless, this problem provides undoubted interest, since calorimetric studies can provide useful information about the thermometric properties of films, phase transformations in them. The problem can be solved by using materials phase transition the metal-insulator in thermal contact with the sample as heat-sensitive elements of the films. The theory of the magnetocaloric effect in uniaxial and polycrystalline ferromagnets taking into account the rotation of magnetization is presented. The issues of creation of new refrigerating machines using the magnetocaloric effect are discussed. The magnetocaloric effect in magnetically ordered single crystals is studied taking into account the processes of magnetization rotation. An expression for the magnetocaloric effect in a ferromagnetic polycrystal is obtained, which well describes the experimental results.