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

摘要

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