Magnetocaloric effect in the Laves phase pseudobinaries (Dy1-cRc)Al2 (R=Er and Ho)

In this work we calculate the magnetocaloric effect in the Laves phase pseudobinaries (Dy1-cErc)Al2 and (Dy1-cHoc)Al2. We use a model Hamiltonian of interacting 4f-spins, including the crystalline electrical field interaction. The 4f spin-spin interaction is treated in an extended mean field approximation, in which the magnitude of the exchange interaction between 4f-spins depends on the type of rare earth ion is occupying the neighboring sites. The calculated isothermal entropy change and the adiabatic temperature change upon variations of the magnetic field are in good agreement with the available experimental data.