Electrically induced ferromagnetic order in irradiated LSMO

Lanthanum Strontium Manganite (La_1-xSr_xMnO₃, LSMO) with the La/Sr ratio of 0.7/0.3 (x=0.3) exhibits a phase transition from the ferromagnetic-metal ground state to the high-temperature paramagnetic-insulator[PS1] state which can be triggered thermally or by the application of an electric field. In LSMO, slight variations in stoichiometry dictate electronic and magnetic properties and thus result in drastic changes to its physical properties. In this work, we show that selectively inducing defects, using focused ion beam irradiation, produces interesting localized resistive switching and magnetic behavior. First, the metal-to-insulator transition is suppressed, and the low temperature resistivity increases by orders of magnitude. Second, contrary to the metal-to-insulator transition in pristine LSMO, we induce an insulator-to-metal transition that shows sudden resistive switching. [IKS2] Third and most notably, the electrically induced metallic phase shows anisotropic magnetoresistance, implying ferromagnetic ordering upon the application of voltage. This work reports previously unobserved resistive switching and magnetic behavior and demonstrates the rich interplay between electronic and magnetic properties, which could be utilized in various emerging technologies like neuromorphic computing.