7.2.5.2.2 Magnetization and Curie temperature

This chapter lists saturation magnetizations, Curie temperatures T_C and spin reorientation temperatures T_sr of R₂Fe₁₇A_x (A = C, N, B, D) as well as of mixed transition metal R₂Fe₁₇C_xN_Y compounds. The thermal variation of magnetization in R₂Fe₁₇C compounds, composition dependence of the Curie temperature in R₂Fe₁₇C, compounds with R = Nd, the dependence of the Curie temperatures on the unit-cell volume for R₂Fe₁₇A_x with R = Gd, Y and Th, and A = C or N, dependence of the average Fe magnetic moment at 5 K on the unit cell volume at RT in samples of the composition Th₂Fe₁₇C_x and Th₂Fe₁₇N_x, and temperature dependence of the magnetic moment in powders of Gd₂Fe₁₇N_2.7 and Tb₂Fe₁₇N_2.7 are shown. The other plots include (i) dependence of oxygen content, nitrogen content and magnetization in a field of 20 kOe on the size, (ii) nitrogen content and magnetization in a field of 20 kOe for at RT versus nitrogenation time t, (iii) dependence of the magnetization in a field of 20 kOe on nitrogen content in Sm₂Fe₁₇N_x at room temperature, and (iv) effect of various substituents M on the magnetic ordering temperatures of Y₂Fe_17-yM_yC, and the corresponding unit cell volume variation, ΔV/V at RT and y = 1. Saturation magnetization at RT, Curie temperature and anisotropy field H_A at RT in Sm₂(Fe_0.09M_0.03)₁₇N_x, room-temperature saturation magnetization of Y₂(Fe_1-yCo_y)₁₇N_x compounds and composition dependence of the saturation magnetization at 4.2 K are figured out. The saturation magnetization and Curie temperatures decrease when Fe is replaced by Mn in Er₂Fe₁₇-based compounds.