Structural and Magnetic Properties of Tb(Fe_l-xNi_x)_11.3Nb_0.7 Compounds

Structural and magnetic properties of Tb(Fe_l-xNi_x)_11.3Nb_0.7 compounds have been investigated. The x-ray diffraction patterns show that all compounds crystallize in the ThMn₁₂-type structure and that all samples are almost of single phase. The lattice constants monotonously decrease with increasing Ni content. The Curie temperature T_c clearly increases and the saturation moment M_s monotonously decreases with increasing Ni content. X-ray diffraction patterns of aligned samples at room temperature show that for x ≤ 0.2 the easy magnetization direction is in the plane while for the x = 0.25 compound the easy magnetization direction is along the c-axis. In the compounds with x ≤ 0.20 spin reorientation occurs above room temperature whereas in the compounds with x > 0.2 there is a spin reorientation below room temperature. It has been found that Ni contributes positively to the T-sublattice moment M_T.