Biaxial strain effect of spin dependent tunneling in MgO magnetic tunnel junctions

TL;DR

This study investigates how biaxial strain affects spin-dependent tunneling in MgO magnetic tunnel junctions, revealing that strain reduces TMR and significantly alters conductance, especially in minority channels.

Contribution

It provides new insights into the impact of biaxial strain on tunneling magnetoresistance and conductance in MgO MTJs using quantum transport calculations.

Findings

Biaxial strain increases conductance in both magnetic configurations.

TMR ratio decreases with increasing biaxial strain.

Minority channel conductance is highly sensitive to strain.

Abstract

We study the effect of strain on magnetic tunnel junctions (MTJ) induced by a diamond like carbon (DLC) film. The junction resistance as well as the tunnel magnetoresistance (TMR) reduces with the DLC film. Non-equilibrium Green's function quantum transport calculations show that the application of biaxial strain increases the conductance for both the parallel and anti-parallel configurations. However, the conductance for the minority channel and for the anti-parallel configuration is significantly more sensitive to strain, which drastically increases transmission through a MgO tunnel barrier, therefore, the TMR ratio decreases with biaxial strain.