Large bias-dependent magnetoresistance in all-oxide magnetic tunnel junctions with a ferroelectric barrier

TL;DR

This study uses first-principles calculations to explore bias-dependent transport in all-oxide magnetic tunnel junctions with ferroelectric barriers, revealing large, switchable magnetoresistance effects for potential sensor applications.

Contribution

It demonstrates the potential for electrically controlling magnetoresistance sign and magnitude in oxide-based MTJs with ferroelectric barriers, a novel insight for spintronic device design.

Findings

Enormous bias-dependent tunneling magnetoresistance values.

Magnetoresistance sign can be switched by altering the ferroelectric state.

Potential for electrically-controlled magnetic sensors.

Abstract

All-oxide magnetic tunnel junctions (MTJs) incorporating functional materials as insulating barriers have the potential of becoming the founding technology for novel multi-functional devices. We investigate, by first-principles density functional theory, the bias-dependent transport properties of an all-oxide SrRuO3/BaTiO3/SrRuO3 MTJ. This incorporates a BaTiO3 barrier which can be found either in a non-ferroic or in a ferroelectric state. In such an MTJ not only can the tunneling magnetoresistance reach enormous values, but also, for certain voltages, its sign can be changed by altering the barrier electric state. These findings pave the way for a new generation of electrically-controlled magnetic sensors.