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

Abstract

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.

Photovoltaic effect and photopolarization in Pb[(Mg1/3Nb2/3)0.68<

“…The electric field and temperature-controllable photovoltage in this landmark ferroelectric crystal should be regarded as key basic findings, illustrating how charge separation relates to FE properties and superposes on charge recombination. The evident separation between remanent and transient effects that has been found here completes the profile of many recent photoelectric observations [28][29][30][31][32][33] and is essential to understand and optimize the photoferroelectric performance. This study paves the way toward future investigations in other compounds as well as composites of the same family to optimize composition-tothe-reported properties relationship.…”

Spintronics

“…Insulators with ferromagnetic, ferroelectric, or even multiferroic ordering have been integrated within spintronic devices, and multifunctional operation explained in terms of the expected nominal property has been demonstrated (Bibes et al, 2011;Garcia et al, 2010;Pantel et al, 2012). Light is emerging as a powerful tool to craft the magnetic properties of simple FMs that are coupled to multiferroic CMOs (Kundys et al, 2012). This explanation is consistent with the observation of Couet et al (2014) of biasinduced oxidation at FE insulating/ferromagnetic metallic interfaces, which is likely generic to all oxide/metal interfaces.…”

Photostriction of strontium ruthenate

“…We expect that the response speed can be further increased by doping57 that we are currently investigating.…”

“…in which R hv and R dark are the resistances of SRO under illuminated and dark conditions, respectively 57 . We determined the wavelength-dependent photoresistance of SRO using different lasers at various wavelengths (325,405,532 and 780 nm).…”