Effect of interfacial strain on spin injection and spin polarization of Co2CrAl/NaNbO3/Co2CrAl magnetic tunneling junction

TL;DR

This study uses first-principles calculations to explore how interfacial strain influences spin injection and polarization in a Co2CrAl/NaNbO3 magnetic tunnel junction, revealing strain-dependent effects on device performance.

Contribution

It provides new insights into the strain-dependent behavior of spin polarization and TMR in magnetic tunnel junctions involving Co2CrAl and NaNbO3.

Findings

Compressive strain preserves spin polarization due to stronger interfacial coupling.

Tensile strain enhances interface states, reducing spin polarization and TMR.

Interfacial strain significantly impacts spintronic device performance.

Abstract

First-principles calculations were carried out to investigate interfacial strain effects on spin injection and spin polarization of a magnetic tunnel junction consisting of half-metallic full-Heusler alloy Co2CrAl and ferroelectric perovskite NaNbO3. Spin-dependent coherent tunneling was calculated within the framework of non-equilibrium Green's function technique. Both spin polarization and tunnel magnetoresistance (TMR) are affected by the interfacial strain but their responses to compressive and tensile strains are different. Spin polarization across the interface is fully preserved under a compressive strain due to stronger coupling between interfacial atoms, whereas a tensile strain significantly enhances interface states and lead to substantial drops in spin polarization and TMR.