Ab initio, theoretical and Monte Carlo approaches for the magnetocaloric effect in DyNi4Si

Abstract The magnetic and magnetocaloric properties of DyNi 4 Si alloys in YNi 4 Si-type orthorhombic structure have been investigated by using a combination of first-principles calculations and mean field theory, effective field theory, and Monte Carlo simulation. We find that Magnetic results of DyNi 4 Si compound show ferromagnetic-type ordering at 19 K, the magnetization-field isotherms for DyNi 4 Si exhibit hysteresis loop at 2 K due to strong magnetic anisotropy. The non-saturating behavior and the value of the magnetic moment of 7.7 μ B /fu in 140 kOe at 2 K where the theoretical value for DyNi 4 Si only is about 10 μ B , this suggest a not completely ordered ferromagnetic state of DyNi 4 Si (Morozkin et al., 2015) [2] . The isothermal entropy changes for H =14 T at T =22 K is −Δ S =15.6 J/(kg K). The obtained results are in good agreement with available experimental data. This study allows the suggestion of the compatible Ising model for a new class of compound YNi 4 Si-type, which shows magnetocaloric behavior at low temperature.