Improvement of high-frequency properties of Co<sub>2</sub>FeSi Heusler films by ultrathin Ru underlayer

Improvement of high-frequency properties of Co₂FeSi Heusler films by ultrathin Ru underlayer

Wang Cuiling^{1, 2}, Zhang Shouheng¹, Li Shandong^{1, †}, Du Honglei^{1, 3}, Zhao Guoxia¹, Cao Derang¹

(a) The typical S₂₁ FMR absorption curves at 0 Oe for Co₂FeSi films with Ru thickness from 0 nm to 5 nm. (b) The experimental (symbols) and fitting (lines) f_r versus H curves of films with various Ru thicknesses of 0 nm–5 nm. The inset is the directions of the applied magnetic field H and the magnetization M of FMR measurements. The t_Ru dependences of self-bias FMR frequency and the fitted 4π M_eff (c), and measured H_K and H_C (d).