Electric Field Effect in Diluted Magnetic Insulator Anatase Co:TiO2

TL;DR

This study demonstrates reversible electric field control of magnetic properties in a high-quality epitaxial oxide heterostructure at room temperature, marking a novel achievement in oxide-based diluted ferromagnets.

Contribution

First demonstration of electric field effect on insulating ferromagnetism in an oxide-based diluted magnetic insulator using epitaxial heterostructures.

Findings

Reversible modulation of magnetic moment by about 15%

Electric field effect is stable over multiple cycles

Mechanisms for modulation are discussed

Abstract

An external electric field induced reversible modulation of room temperature magnetic moment is achieved in an epitaxial and insulating thin film of dilutely cobalt-doped anatase TiO2. This first demonstration of electric field effect in any oxide based diluted ferromagnet is realized in a high quality epitaxial heterostructure of PbZr0.2Ti0.8O3/Co:TiO2/SrRuO3 grown on (001) LaAlO3. The observed effect, which is about 15% in strength in a given heterostructure, can be modulated over several cycles. Possible mechanisms for electric field induced modulation of insulating ferromagnetism are discussed.