  Phase separation naturally occurs in a variety of magnetic materials and it
often has a major impact on both electric and magnetotransport properties. In
resistive switching systems, phase separation can be created on demand by
inducing local switching, which provides an opportunity to tune the electronic
and magnetic state of the device by applying voltage. Here we explore the
magnetotransport properties in the ferromagnetic oxide (La,Sr)MnO3 (LSMO)
during the electrical triggering of an intrinsic metal-insulator transition
(MIT) that produces volatile resistive switching. This switching occurs in a
characteristic spatial pattern, i.e., the formation of an insulating barrier
perpendicular to the current flow, enabling an electrically actuated
ferromagnetic-paramagnetic-ferromagnetic phase separation. At the threshold
voltage of the MIT triggering, both anisotropic and colossal magnetoresistances
exhibit anomalies including a large increase in magnitude and a sign flip.
Computational analysis revealed that these anomalies originate from the
coupling between the switching-induced phase separation state and the intrinsic
magnetoresistance of LSMO. This work demonstrates that driving the MIT material
into an out-of-equilibrium resistive switching state provides the means to
electrically control of the magnetotransport phenomena.
