Simultaneous laser excitation of backward volume and perpendicular standing spin waves in full-Heusler Co2FeAl0.5Si0.5 films

Zhifeng Chen,Shufa Li,Yong Yan,Yong Jiang,Xiaoguang Xu,Tianshu Lai

doi:10.1038/srep42513

Abstract

Spin-wave dynamics in full-Heusler Co2FeAl0.5Si0.5 films are studied using all-optical pump-probe magneto-optical polar Kerr spectroscopy. Backward volume magnetostatic spin-wave (BVMSW) mode is observed in films with thickness ranging from 20 to 100 nm besides perpendicular standing spin-wave (PSSW) mode, and found to be excited more efficiently than the PSSW mode. The field dependence of the effective Gilbert damping parameter appears especial extrinsic origin. The relationship between the lifetime and the group velocity of BVMSW mode is revealed. The frequency of BVMSW mode does not obviously depend on the film thickness, but the lifetime and the effective damping appear to do so. The simultaneous excitation of BVMSW and PSSW in Heusler alloy films as well as the characterization of their dynamic behaviors may be of interest for magnonic and spintronic applications.

Highlights

Specific combination of the dynamic observation of BVMSW and perpendicular standing spin wave (PSSW) in Heusler alloy films using time-resolved magneto-optical Kerr (TR-MOKE), and the characterization of such SWMs, may be of interest for magnonic and spintronic applications
To identify the SWMs, the spectrum of spin waves for different H is obtained by extracting the oscillatory components from the magnetization dynamics and carrying out the fast Fourier transform (FFT)
Since the probing area in our experiment is located in the excited area which can be regarded as the source of spin wave, the propagation can accelerate the decay of spin precession in the probing area[24]

Summary

Introduction

Specific combination of the dynamic observation of BVMSW and PSSW in Heusler alloy films using TR-MOKE, and the characterization of such SWMs, may be of interest for magnonic and spintronic applications. Spin-wave dynamics are excited and measured using a TR-MOKE configuration with an outof-plane external field applied.

Results

Conclusion