The effect of Zr substitution on saturation magnetization in (Sm1-xZrx)(Fe0.8Co0.2)12 compound with the ThMn12 structure

Zr is one of the essential elements to stabilize the ThMn12 structure in rare earth (R) transition metal (M) hard magnetic compounds, RM12. In this work, the effects of Zr on the intrinsic hard magnetic properties of (Sm1-xZrx)(Fe0.8Co0.2)(12) compounds are investigated using epitaxially grown thin films. The increase of Zr substitution for Sm from x = 0 to 0.26 for (Sm1-xZrx)(Fe0.8Co0.2)(12) increases saturation magnetization (mu M-0(s)) from 1.78 T to 1.90 T, the highest value reported for hard magnetic compounds. The largest mu H-0(a) and T-c for Zr-doped samples were found to be 9.8 T and 671 K for x = 0.18 which is superior to those for Nd2Fe14B. Sm-rich Sm1.30Zr0.27(Fe0.8Co0.2)(12), obtained as sub-mu m thick films, has remanence, mu M-0(r) of 1 T, which appears to be useful for near-field applications such as micro-electro-machines and magnetic recording media if microstructure can be optimized to obtain a sufficient coercivity. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.