Perpendicular magnetic anisotropy in Pt/Fe multilayers

Abstract

Perpendicular magnetic anisotropy (K_⊥) and related magnetic properties in Pt/Fe multilayers [compositionally modulated multilayer films (CMFs)] are investigated. It is found that Pt/Fe CMFs with about an 18‐Å Pt layer and Fe layer below 5 Å become perpendicularly magnetized films. Surface magnetic anisotropy (K_s) and volume anisotropy (K_v) are 0.46 erg/cm² and about − 2 × 10⁷ erg/cm³ at room temperature, respectively. The K_s is almost equivalent to that of Pt/Co CMFs and increases with decreasing temperature. The absolute value of K_v, however, is much larger than that of the Pt/Co system. The effective magnetic anisotropy (K_⊥ eff) of [Fe(4.7 Å)/Pt(18.5 Å)]₈₀ CMF changes from positive to negative at T≂200 K with decreasing temperature.