Half-metallic ferromagnets for magnetic tunnel junctions

TL;DR

This paper emphasizes the importance of eliminating interface states at the Fermi level in half-metallic ferromagnets for TMR devices and proposes a first-principles design of an antiferromagnetically coupled TMR element supported by ab-initio calculations.

Contribution

It introduces a theoretical framework and design principles for optimizing half-metallic ferromagnets in tunneling magnetoresistance applications, supported by first-principles calculations.

Findings

Interface states must be eliminated for effective TMR.

Proposed an antiferromagnetically coupled TMR design.

Supported conclusions with ab-initio calculations.

Abstract

Using theoretical arguments, we show that, in order to exploit half-metallic ferromagnets in tunneling magnetoresistance (TMR) junctions, it is crucial to eliminate interface states at the Fermi level within the half-metallic gap; contrary to this, no such problem arises in giant magnetoresistance elements. Moreover, based on an a priori understanding of the electronic structure, we propose an antiferromagnetically coupled TMR element, in which interface states are eliminated, as a paradigm of materials design from first principles. Our conclusions are supported by ab-initio calculations.