Analytical model to understand the colossal magnetocaloric effect

摘要

We report the theoretical investigations on the colossal magnetocaloric effect using a simple model that couples the lattice entropy and magnetic entropy through the magnetoelastic deformation. Analytical expressions were obtained for the thermodynamic magnetic state equation as well as for the total entropy and heat capacity. The coupled magnetic lattice model predicts high isothermal entropy changes due to the lattice contribution for external magnetic field change, overcoming the magnetic entropy change limit.