Tunable magnetization relaxation of Fe(2)Cr(1−x)Co(x)Si half-metallic Heusler alloys by band structure engineering

Authors: Shikun He , Yifan Liu, Yuhong Zheng, Qing Qin, Zhenchao Wen, Qingyun Wu, Yi Yang, Yupu Wang, YuanPing Feng, Kie Leong Teo, and Christos Panagopoulos

Published in: Physical Review Materials, 2017.

We report a systematic investigation on the magnetization relaxation properties of iron-based half-metallic Heusler alloy Fe(2)Cr(1−x)Co(x)Si (FCCS) thin films using broadband angular-resolved ferromagnetic resonance. Band structure engineering through Co doping (x) demonstrated by first-principles calculations is shown to tune the intrinsic magnetic damping over an order of magnitude, namely 1 × 10exp(-2) – 8 × 10exp(−4). Notably, the intrinsic damping constants for samples with high Co concentration are among the lowest reported for Heusler alloys and even comparable to magnetic insulator yttrium iron garnet. Furthermore, a significant reduction of both isotropic and anisotropic contributions of extrinsic damping of the FCCS alloys was found in the FCCS films with x = 0.5 –0.75, which is of particular importance for applications. These results demonstrate a practical recipe to tailor functional magnetization for Heusler alloy-based spintronics at room temperature.

Read more