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

We present a magnetoresistive—photoresistive device based on the interaction of a piezomagnetic CoFe thin film with a photostrictive BiFeO3 (BFO) 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.