Magnetoelastic coupling influence on the magnetocaloric effect in ferromagnetic materials

The Landau theory for phase transitions framework is applied to describe the magnetocaloric effect in ferromagnetic systems with magnetoelastic and magnetoelectronic couplings. The M-4 coefficient in the energy expansion, whose signal determines the order of the phase transition, and its temperature dependence, are shown to be of crucial importance. The existence of a broad magnetic entropy peak above T-C is related to these couplings. (C) 2004 Elsevier B.V. All rights reserved.