Temperature Dependence of Perpendicular Magnetic Anisotropy in Fe/Pt Compositionally Modulated Multilayer Films

The temperature dependences of the magnetization and magnetic anisotropy of Fe/Pt compositionally modulated multilayer films (CMFs) prepared by rf sputtering were investigated. The magnitude of the surface magnetic anisotropy K
_s
of Fe/Pt CMFs is nearly equal to that of Co/Pt CMFs at 77K and at room temperature. The absolute value of the volume magnetic anisotropy K
_v
of Fe/Pt CMFs is about twice as large as that of Co/Pt CMFs. The K
_s
obtained from CMFs with thick Fe layers seems to remain nearly constant as the temperature is varied. However, K
_v
decreases gradually with increasing temperature in the case of Fe/Pt CMFs. The relation between the saturation magnetization M
_s
(T) and the perpendicular magnetic anisotropy K
_⊥
(T) are discussed.