Photo-control of exchange bias in a Co${}_{90}$Fe${}_{10}$/BiFeO${}_3$ heterostructure

Control of magnetism in multiferroic heterostructures is highly motivated in information technology. Herein, a photo-controlled exchange bias in a Co${}_{90}$Fe${}_{10}$/BiFeO${}_3$(BFO)/SrRuO${}_3$/SrTiO${}_3$ heterostructure at room temperature under ultraviolet light (λ: 375 nm) is reported. The impact of ultraviolet light on exchange bias is investigated by magnetic property and magnetoresistance measurement. It is found that the exchange bias field of the Co${}_{90}$Fe${}_{10}$/BFO interface is reduced under the UV light irradiation. The possible reason is due to the change of in-plane compressive strain of BFO under the light irradiation, giving rise to the regulation of surface magnetic moment of BFO. The results indicate that a photo-control of exchange bias in Co${}_{90}$Fe${}_{10}$/BFO heterostructures through strain-modulated multiferroic BFO film could be achieved at room temperature. (© 2022 Wiley‐VCH GmbH)