The unique magnetic damping enhancement in epitaxial Co2Fe1−xMnxAl films**Project supported by the Natural Science Foundation of Guangdong Province, China (Grant No. 2015A030310003) and the Program for Scientific Research Start-up Funds of Guangdong Ocean University, China.

Abstract

Uniform precession dynamics and its magnetic damping are investigated in epitaxial Co2Fe1−xMnxAl films by using the time-resolved magneto–optical Kerr effect under out-of-plane configuration. The decay time of uniform precession mode decreases, and thus the magnetic damping increases with the increase of external field. Moreover, the decay time decreases as x decreases, so that the enhancement of magnetic damping occurs in Fe-rich sample. Furthermore, the decay time decreases as the excitation fluence increases, which drops rapidly at low magnetic field comparing with the slow reduction at high magnetic field. This unique magnetic damping enhancement is attributed to the enhancement of homogeneous magnetization.