Low-field positive magnetoresistance near room temperature in three-component perovskite-type artificial superlattices

Perovskite-type superlattices consisting of La0.9Sr0.1MnO3, LaAlO3, and SrTiO3 were fabricated on (001) SrNb0.01Ti0.99O3 substrates by laser molecular beam epitaxy. The three-component superlattice exhibited desirable low-field magnetoresistance effects. At a given current bias of 10 mu A, positive magnetoresistance ratio was enhanced from 2% to 15% and 22% with increasing temperatures from 15 to 300 and 325 K at 300 Oe, at which a maximum value occurred from the external magnetic field dependence of magnetoresistance. The nature of the enhanced magnetoresistance is discussed in connection to the interfacial effect. (C) 2007 American Institute of Physics.