Investigation on the magnetocaloric effect in DyNi2, DyAl2 and Tb1−Gd Al2 (n=0, 0.4, 0.6) compounds

Abstract The magnetocaloric effect (MCE) in the DyNi 2 , DyAl 2 and Tb 1− n Gd n Al 2 ( n =0, 0.4, 0.6) was theoretically investigated in this work. The DyNi 2 and DyAl 2 compounds are described considering a model Hamiltonian which includes the crystalline electrical field anisotropy. The anisotropic MCE was calculated changing the magnetic field direction from 〈1 1 1〉 to 〈0 0 1〉 in DyNi 2 and from 〈1 0 0〉 to 〈0 1 1〉 in DyAl 2 . The influence of the second- and first-order spin-reorientation phase transitions on the MCE that occurs in these systems is discussed. For the calculations of the MCE thermodynamic quantities in the Tb 1− n Gd n Al 2 systems we take into account a two sites magnetic model, and good agreement with the available experimental data was obtained.