Size dependent electric voltage-controlled magnetic anisotropy in multiferroic heterostructures: Interface-charge and strain co-mediated magnetoelectric coupling

TL;DR

This paper investigates how electric voltage can control magnetic anisotropy in ferromagnetic/ferroelectric heterostructures, emphasizing the size-dependent transition between interface-charge and strain-mediated magnetoelectric coupling mechanisms.

Contribution

It introduces a phenomenological model that explains the size-dependent dominance of interface-charge and strain-mediated couplings in magnetoelectric effects.

Findings

Interface-charge coupling dominates below a critical thickness dtr.

Strain-mediated coupling becomes dominant above dtr.

The model explains size-dependent variations in magnetic anisotropy.

Abstract

We present a phenomenological scheme to study the size-dependent electric voltage-controlled magnetic anisotropy in ferromagnetic (FM)/ferroelectric (FE) heterostructures. The FM layers are either metallic Fe(001), Ni(001), Co(0001), or half-metallic (La, Sr)MnO3 films. Two magnetoelectric mechanisms, i.e., interface-charge and strain-mediated couplings, are considered. We show that the interface-charge mediated coupling is the main mechanism for the magnetoelectic coupling when the FM film thickness is below a certain transition thickness dtr while the strain-mediated coupling dominates above dtr.