These results stem from strain-mediated magnetoelectric coupling. The applied electric field causes changes in the coercivity and the squareness ratio of the films, suggesting a reorientation of the effective magnetic easy axis in Fe80Ga20. However, larger HEB values are observed when the squareness ratio is lower. It is claimed that the effect of voltage is equivalent to an in-plane component of an applied magnetic field oriented perpendicular to the cooling field direction. Perpendicular in-plane magnetic fields have been shown to induce an increase in exchange bias in some ferromagnetic/antiferromagnetic systems due to partial recovery of the untrained antiferromagnetic state. Remarkably, here, this effect is directly induced with voltage, therefore enhancing energy efficiency.
This work was supported by TÜBİTAK (The Scientific and Technological Research Council of Turkey) through the Project No. 1059B192000016. Partial financial support by the European Research Council (MAGIC-SWITCH 2019-Proof of Concept Grant, Agreement No. 875018), the European Union's Horizon 2020 research and innovation programme (European Training Network, ETN/ITN Marie Skłodowska-Curie, Agreement No. 861145), the Spanish Government (Nos. Severo Ochoa FUNFUTURE-CEX2019-000917-SMCIN, AEI/10.13039/501100011033-, MAT2017-86357-C3-1-R, PID2019-107727RB-I00, PID2020-116844RB-C21, and PDC2021-121276-C31), the Generalitat de Catalunya (No. 2017-SGR-292), and the European Regional Development Fund (No. MAT2017-86357-C3-1-R) is acknowledged. E.M. is a Serra Húnter Fellow. A.Q. acknowledges the Spanish Ministry of Science, Innovation and Universities for the Juan de la Cierva Formación Contract (No. FJC2019-039780-I).