Possible origin of nonlinear magnetic anisotropy variation in electric field effect in a double interface system

TL;DR

This study uses density functional theory to explore how electric fields influence magnetic anisotropy at a double interface, revealing complex electron-dependent behaviors and potential electron leakage effects.

Contribution

It uncovers the nonlinear relationship between electric fields and magnetic anisotropy, emphasizing the role of electronic structure and interface charge dynamics.

Findings

MAE increases with electron depletion and certain accumulation conditions

Variation in MAE linked to electron leakage at the interface

Electronic structure analysis explains the anisotropy changes

Abstract

We investigated the effect of an electric field on the interface magnetic anisotropy of a thin MgO/Fe/MgO layer using density functional theory. The perpendicular magnetic anisotropy energy (MAE) increases not only under electron depletion but also under some electron accumulation conditions, showing a strong correlation with the number of electrons on the interface Fe atom. The reverse variation in the MAE under the electric field is ascribed to novel features on the charged interface, such as electron leakage. We discuss the origin of the variation in terms of the electronic structures.