Structural and Magnetic Properties of Sm₂Fe_17—xMn_xN_y with 0 ≤ x ≤ 6 and y ≈︂ 3

The crystallographic and magnetic properties of the pseudo-binary Sm₂Fe_17—xMn_x solid solution and its nitride, have been extensively studied. Mn substitution of Fe does not change the structure of Sm₂Fe₁₇. The substitution of iron by manganese decreases the parameters a, c and the unit-cell volume in the range of 0 ≤ x ≤ 2, then it increases. The Curie temperature and the saturation magnetisation decrease with increasing Mn content. The easy magnetisation direction is perpendicular to the c-axis in the region x ≤ 2, and after it changes into parallel to the c-axis. The insertion of nitrogen in the substituted compounds increases the crystallographic and magnetic properties. The parameter a of the nitride alloys decreases with Mn content for 0 ≤ x ≤ 2, then it increases. However, the parameter c of all the nitrides increases with increasing Mn content. The Curie temperature and the saturation magnetisation decrease with increasing Mn concentration. Finally, all the nitrides exhibit an easy magnetisation direction parallel to the c-axis.