Intrinsic hard magnetic properties of Sm(Fe,Co)_12−xTi_x compound with ThMn₁₂ structure

Sm_1.1(Fe_0.8Co_0.2)_12-xTi_x thin films were grown epitaxially with various Ti contents (x = 0, 0.4, 0.6, 0.9, and 1) to investigate the effects of Ti on the intrinsic hard magnetic properties and phase stability. A single ThMn₁₂-type structure with the (001) texture was obtained for x up to 0.9. A further increase in the Ti content led to a multiphase structure in the Sm1.1(Fe_0.8Co_0.2)₁₁Ti₁ film; this was in contrast to the behavior in the bulk, where x = 1 is necessary to form a single ThMn₁₂-type structure. Meanwhile, increasing the Ti content from x = 0–0.6 in the Sm_1.1(Fe_0.8Co_0.2)_12-xTi_x thin films decreased the saturation magnetization, anisotropy field, and Curie temperature from 1.84 T to 1.55 T, 12–8.7 T, and 800–730 K, respectively. This thin film model shows that the Sm(Fe_0.8Co_0.2)_12-xTi_x compounds can compete with Nd₂Fe₁₄B at 300 K when phase stabilization is achieved at reduced Ti content, for x ≤ 0.5.