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

摘要

Perovskite-type superlattices consisting of La_(0.9)Sr_(0.1)MnO_3, LaAlO_3, and SrTiO_3 were fabricated on (001) SrNb_(0.01)Ti_(0.99)O_3 substrates by laser molecular beam epitaxy. The three-component superlattice exhibited desirable low-field magnetoresistance effects. At a given current bias of 10 μA, 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.