Perpendicular magnetic anisotropy and thermal stability in Co_2FeAl_(0.5)Si_(0.5)/Pt multilayers

摘要

Perpendicular magnetic anisotropy (PMA) and thermal stability of Co_2FeAl_(0.5)Si_(0.5) (CFAS)/Pt multilayer structure prepared by dc magnetron sputtering have been studied. It is found that the strength of PMA depends on the thickness of CFAS layer, and the maximum effective thickness of CFAS with PMA is demonstrated to be about 1.5 nm. The interfacial anisotropy energy K_s is estimated to be 0.45 erg/cm~2, which is larger than those of Co/Pd and Co/Ni multilayers and responsible for the strong PMA of the CFAS/Pt multilayer. The annealing treatments will give rise to the loss of PMA of CFAS/Pt multilayer and has the relatively less influence with large period number N. With the increasing of the period number N, the CFAS/Pt multilayers tend to have wasp-waist-shaped easy-axis hysteresis loops and multidomain structures.