Current switching of resistive states in magnetoresistive manganites

Abstract

Magnetoresistive devices (based on, for example, magnetic multilayers) exhibit large changes in electrical resistance in response to a magnetic held, which has led to dramatic improvements in the data density and reading speed of magnetic recording systems. Manganese oxides having a perovskite structure (the so-called manganites) can exhibit a magnetoresistive response that is many orders of magnitude larger than that found for other materials, and there is therefore hope that these compounds might similarly be exploited for recording applications. Here we show that the switching of resistive states in the manganites can be achieved not only by a magnetic field, but also by an electric field. For manganites of the form Pr(1-x)Ca(x)MnO3, we find that an electrical current (and by implication a static electric field) triggers the collapse of the low-temperature, electrically insulating charge- ordered state to a metallic ferromagnetic state. We suggest that such a phenomenon could be exploited to pattern conducting ferromagnetic domains within an insulating antiferromagnetic matrix, and so provide a route for fabricating micrometre- or nanometre-scale electromagnets.