Magnetoresistance anomaly during electrical triggering of a metal-insulator transition*

Combing resistive switching and spintronic functionalities in a single device is an exciting opportunity to bring together the advantages of charge- and spin-based electronics, enriching the design space for practical applications, and to further the basic understanding of interactions between electrical and magnetic properties of materials. Here we explored magnetotransport in ferromagnetic oxide (La,Sr)MnO₃ (LSMO) during electrical triggering of the intrinsic metal-insulator transition (MIT), which produces volatile resistive switching. This switching occurs in a characteristic spatial pattern, the formation of a paramagnetic insulating barrier perpendicular to the current flow, in contrast to the conventional filamentary percolation parallel to the current. At the threshold voltage of the MIT triggering, we observed strong anomalies including large magnitude increase and flipping of the sign of anisotropic and colossal magnetoresistances. The computational analysis revealed that these anomalies are due to the coupling between the voltage induced paramagnetic insulating barrier formation and intrinsic magnetoresistance. Our work demonstrates a novel approach to manipulate magnetic properties by electrically driving the material into the out-of-equilibrium resistive switching state.