Synthesis, structure, and magnetic properties

A compound (Formula presented) has been synthesized successfully and its crystal structure has been investigated by x-ray powder diffraction. It belongs to the (Formula presented) earth) family with (Formula presented) and (Formula presented) The space group is (Formula presented) The lattice parameters are (Formula presented) and (Formula presented) Each unit cell contains one formula unit of (Formula presented) and there are nine kinds of equivalent positions in each unit cell, i.e., (Formula presented) and (Formula presented) which are occupied by (Formula presented) and (Formula presented) respectively. Magnetic measurements indicate that this compound is ferromagnetic with a Curie temperature of 380 K. Its saturation magnetic moment at 5 K and room temperature are (Formula presented) and (Formula presented) respectively. Based on the experimental results of the saturation magnetization, three kinds of Co sites with different magnetic moment are proposed. The (Formula presented) compound exhibits huge planar anisotropy with an anisotropy field of 250 kOe at 5 K. No spin reorientation was detected from the temperature dependence of the magnetization and the temperature dependence of the ac susceptibility curves from 5 K to room temperature. The behavior of magnetocrystalline anisotropy is analyzed using the single-ion model.