Tunneling anisotropic magnetoresistance driven by magnetic phase transition

TL;DR

This paper demonstrates a novel tunneling anisotropic magnetoresistance effect driven by magnetic phase transition in alfa-FeRh-based junctions, achieving significant room-temperature MR ratios with potential applications in spintronics.

Contribution

It introduces a new method to realize tunneling anisotropic magnetoresistance using phase transition in alfa-FeRh, without needing two magnetic electrodes.

Findings

Achieved up to 20% MR ratio at room temperature.

MR polarity and magnitude can be tuned via interfacial engineering.

Demonstrated potential for applications in magnetic memory and spintronics.

Abstract

The independent control of two magnetic electrodes and spin-coherent transport in magnetic tunnel junctions are strictly required for tunneling magnetoresistance, while junctions with only one ferromagnetic electrode exhibit tunneling anisotropic magnetoresistance dependent on the anisotropic density of states with no room temperature performance so far. Here we report an alternative approach to obtaining tunneling anisotropic magnetoresistance in alfa-FeRh-based junctions driven by the magnetic phase transition of alfa-FeRh and resultantly large variation of the density of states in the vicinity of MgO tunneling barrier, referred to as phase transition tunneling anisotropic magnetoresistance. The junctions with only one alfa-FeRh magnetic electrode show a magnetoresistance ratio up to 20% at room temperature. Both the polarity and magnitude of the phase transition tunneling anisotropic magnetoresistance can be modulated by interfacial engineering at the alfa-FeRh/MgO interface. Besides the fundamental significance, our finding might add a different dimension to magnetic random access memory and antiferromagnet spintronics.