Thermal Stability and Electrical Control of Magnetization of Heusler/Oxide Interface and Non-collinear Spin Transport of Its Junction

TL;DR

This study uses first-principles calculations to analyze the thermal stability and electric field control of magnetization at the Co2FeAl/MgO interface, demonstrating high stability and significant magnetoelectric effects for spintronic applications.

Contribution

It provides a detailed phase diagram of the CFA/MgO interface's thermal stability and reveals electric-field-induced giant modifications of magnetic anisotropy, advancing spintronic device design.

Findings

Interfacial perpendicular-anisotropy from Fe-O hybridization enhances thermal stability.

Electric field induces a giant change in magnetic anisotropy energy.

High spin polarization and good magnetoresistance in CFA/MgO/CFA junctions.

Abstract

Towards next-generation spintronics devices, such as computer memories and logic chips, it is necessary to satisfy high thermal stability, low-power consumption and high spin-polarization simultaneously. Here, from first-principles, we investigate thermal stability (both structure and magnetization) and the electric field control of magnetic anisotropy on Co2FeAl (CFA)/MgO. A phase diagram of structural thermal stability of the CFA/MgO interface is illustrated. An interfacial perpendicular-anisotropy, coming from the Fe-O orbital hybridization, provides high magnetic thermal stability and a low stray field. We find an electric-field-induced giant modification of such perpendicular-anisotropy via a great magnetoelectric effect (the anisotropy energy coefficient beta~10-7 erg/V cm). Our spin electronic-structure and non-collinear transport calculations indicate high spin-polarized interfacial states and good magnetoresistance properties of CFA/MgO/CFA perpendicular magnetic tunnel junctions.