Theoretical investigations on the magnetocaloric and barocaloric effects in TbyGd(1−y)Al2 series

Abstract

We report the calculations on the magnetocaloric and barocaloric effects in ferromagnetic series TbyGd(1−y)Al2. Our model includes the crystalline electrical field interaction, exchange interactions among Tb–Tb, Gd–Gd and Tb–Gd magnetic ions and the Zeeman effect for an anisotropic system. The lattice and electronic entropies were included in adiabatic processes. The magnetocaloric effect calculated for magnetic field changes along the easy magnetic direction 〈111〉 is in good agreement with the experimental data. Calculation along the hard magnetization direction 〈001〉 predicts anomalous magnetocaloric effect, which was ascribed to the spin reorientation processes. From the available experimental data of Curie temperature dependence on pressure, the exchange model parameters were scaled and the barocaloric effect was calculated.