Structure and magnetic properties of (Pr_xDy_1-x)Fe_10.5V_1.5 compounds and their nitrides

The structural and magnetic properties of (Pr_xDy_1-x)Fe_10.5V_1.5 compounds (x = 0 - 0.8) and their nitrides have been investigated by X-ray diffraction and magnetic measurements. It is found that single-phase V-stabilized (Pr_xDy_1-x)Fe_10.5V_1.5 compounds can be formed in the Pr content range x = 0-0.8. The substitution of Dy for Pr in the compounds results in the decrease in the lattice parameters and saturation magnetization. The easy magnetization direction at room temperature turns from easy c-axis for x = 0-0.3 to easy plane for x = 0.4-0.8, while the Curie temperatures remain almost unaffected by the substitution of Dy, with T_C values of about 590 K. Upon nitrogenation, the Curie temperature is increased to around 820 K, and the saturation magnetization increases by approximately 20%, while the easy magnetization direction lies along c-axis in the temperature range 0 K to T_C. At low Dy contents, the (Pr_xDy_1-x)Fe_10.5V_1.5N_y compounds have excellent intrinsic magnetic properties favourable for permanent magnet applications.