%A Cuiling Wang(王翠玲), Shouheng Zhang(张守珩), Shandong Li(李山东), Honglei Du(杜洪磊), Guoxia Zhao(赵国霞), Derang Cao(曹德让) %T Improvement of high-frequency properties of Co2FeSi Heusler films by ultrathin Ru underlayer %0 Journal Article %D 2020 %J Chin. Phys. B %R 10.1088/1674-1056/ab7802 %P 46202-046202 %V 29 %N 4 %U {https://cpb.iphy.ac.cn/CN/abstract/article_122384.shtml} %8 2020-04-05 %X Heusler Co2FeSi films with a uniaxial magnetic anisotropy and high ferromagnetic resonance frequency fr were deposited by an oblique sputtering technique on Ru underlayers with various thicknesses tRu from 0 nm to 5 nm. It is revealed that the Ru underlayers reduce the grain size of Co2FeSi, dramatically enhance the magnetic anisotropy field HK induced by the internal stress from 242 Oe (1 Oe=79.5775 A·m-1) to 582 Oe with an increment ratio of 2.4, while a low damping coefficient remains. The result of damping implies that the continuous interface between Ru and Co2FeSi induces a large in-plane anisotropic field without introducing additional external damping. As a result, excellent high-frequency soft magnetic properties with fr up to 6.69 GHz are achieved.