Magnetocrystalline anisotropy and spin reorientation transition of HoMn6Sn6 compound

The spin reorientation transition of intermetallic compound HoMn6Sn6 has been investigated by applying the molecular field theory. The temperature dependence of easy magnetization direction of compound and the magnetic moment directions of Ho and Mn ions are theoretically calculated and have good agreement with the experimental data. In the framework of single ion model, the temperature dependence of magnetocrystalline anisotropic constants K1R and K2R of Ho ion has also been calculated. Our studies show that the fourth-order crystal field parameter B40 and the corresponding second-order magnetocrystalline anisotropic constant K2R of Ho ion have to be taken into account in order to explain the spin reorientation transition satisfactorily. The competition between K2R and K1R plays a key role in the spin reorientation transition of HoMn6Sn6.