Theoretical investigation of the giant magnetocaloric effect in Er0.7Tm0.3Al2

This study presents a theoretical investigation of the giant magnetocaloric effect recently reported in the intermetallic compound Er _0.7Tm _0.3Al ₂. Our model Hamiltonian includes the crystalline electrical field, exchange, and Zeeman interactions in both Er ³⁺ and Tm ³⁺ sublattices. A remarkable agreement was achieved between the theoretical calculations and experimental data concerning heat capacity, Δ S T and Δ T ad (magnetocaloric quantities). Additionally, the analysis of magnetic anisotropy and simulations for the rotating magnetocaloric effect in Er _{0. 7}Tm _0.3Al ₂ were performed. The maximum value for the rotating magnetocaloric effect was predicted around the temperature of spin reorientation transition from the <111>-easy to the <001>-hard magnetization directions.