Light controlled magnetoresistance and magnetic field controlled photoresistance in CoFe film deposited on BiFeO3

TL;DR

This study demonstrates a device where light-induced strain in BiFeO3 controls the magnetoresistance and photoresistance of an overlaid CoFe film, enabling light and magnetic field tunable magnetic properties.

Contribution

It introduces a novel light-controlled magnetoresistive device leveraging piezomagnetic and photostrictive effects in CoFe/BiFeO3 heterostructures.

Findings

Resistance and magnetoresistance are tunable by light wavelength.

Light decreases anisotropic magnetoresistance via magnetoelastic effects.

Potential applications in photo-sensing and magnetic memory devices.

Abstract

We present a magnetoresistive-photoresistive device based on the interaction of a piezomagnetic CoFe thin film with a photostrictive BiFeO3 substrate that undergoes light-induced strain. The magnitude of the resistance and magnetoresistance in the CoFe film can be controlled by the wavelength of the incident light on the BiFeO3. Moreover, a light-induced decrease in anisotropic magnetoresistance is detected due to an additional magnetoelastic contribution to magnetic anisotropy of the CoFe film. This effect may find applications in photo-sensing systems, wavelength detectors and can possibly open a research development in light-controlled magnetic switching properties for next generation magnetoresistive memory devices.