Role of magnetocrystalline anisotropy on anisotropic magnetocaloric effect in single crystals

Abstract

The role of magnetocrystalline anisotropy in single crystals played on the anisotropic magnetocaloric effect is studied based on Monte Carlo simulation. By taking into account the anisotropy, the spin reorientation transition (SRT) temperature (TSRT) may be higher than the Curie temperature and enhanced with larger anisotropy, and the magnetization behaviors at low temperatures below TSRT and under weak fields are highly sensitive to the anisotropy. The anisotropy of entropy change is the most significant when the magnetic field is parallel to the easy axis, while the maximum entropy change may increase or decrease with the anisotropy constant in a given direction depending on the magnetic field strength. Power-law fits have been conducted on the field dependence of the maximum entropy change and relative cooling power, which not only indicate a characteristic of the second-order phase transition but also demonstrate effect of anisotropy on magnetic order and dynamics during the SRT to contribute to the anisotropic magnetocaloric effect.