Magnetocaloric Effect of Mn₂YSn (Y = Sc, Ti, V) Alloys

Abstract

Abstract—In this paper, the structural, magnetic, and thermodynamic properties of Mn2YSn (Y = Sc, Ti, and V) alloys are considered depending on the applied pressure using the density functional theory and the Monte Carlo method. It is shown that for each compound there are two magnetic states with a low and a high magnetic moment at a smaller and larger unit cell volume, separated by an energy barrier. The barrier value depends on the applied external pressure. The two phases become almost equal in energy at critical pressures of 3.4, –2.9, and –3.25 GPa for Mn2ScSn, Mn2TiSn, and Mn2VSn, respectively. The temperature behavior of the magnetization and magnetocaloric characteristics for the studied phases at various pressures is obtained. Accounting for pressure leads to an understanding of the mechanism of the increase in the magnetocaloric effect in the phase with a high magnetic moment. The greatest effect (ΔSmag ≈ 0.158 J/mol K and ΔTad ≈ 1.1 K) is predicted for Mn2TiSn at a pressure of –2.9 GPa and a change in the magnetic field from 0 to 2 T.