Increased perpendicular magnetocrystalline anisotropy governed by magnetic boundary in an asymmetrically terminated FeRh(001) thin film

TL;DR

This study demonstrates that asymmetrically terminated FeRh(001) thin films exhibit significantly increased perpendicular magnetocrystalline anisotropy energy, primarily influenced by Rh atoms at the magnetic boundary, revealing new insights into magnetic boundary effects.

Contribution

It uncovers the role of magnetic boundary in enhancing perpendicular MCA in asymmetrically terminated FeRh(001) films, a novel finding in magnetic thin film research.

Findings

Rh surface only FM state shows 40% increased perpendicular MCA energy.

Increased MCA energy is governed by Rh atoms at the magnetic boundary.

Spin-orbit coupling contributions are linked to mixed FM and G-AFM states at the boundary.

Abstract

Rh-terminated FeRh(001) film is known to be stable in a ferromagnetic (FM) state different from a G-type antiferromagnetic (G-AFM) bulk ground state, while an Fe-terminated FeRh(001) film has the same ground state as the bulk. In this paper, we investigate the magnetic properties of asymmetrically terminated FeRh(001) films: one surface is Fe-terminated and the other is Rh-terminated. Rh surface only ] (RhSO) FM state in asymmetrically terminated FeRh(001) film is identified to exhibit 40% increased perpendicular MCA energy as compare to that of the whole-layer (WL) FM state. This increased MCA energy is governed by Rh atom which is placed at the magnetic boundary. Since FM and G-AFM states are mixed up at the magnetic boundary, spin-orbit couplings which give positive contribution to perpendicular MCA are revealed.