Magnetoresistance and interlayer exchange coupling in perovskite manganite junctions

Abstract We study magnetoresistance (MR) and interlayer exchange coupling (IEC) in perovskite manganite junctions. We show that in La 2/3 Sr 1/3 MnO 3 /SrTiO 3 /La 2/3 Sr 1/3 MnO 3 tunneling junctions, the MR ratio remains finite up to high temperatures near T C of bulk manganites. In the case of La 2/3 Ba 1/3 MnO 3 /LaNiO 3 /La 2/3 Ba 1/3 MnO 3 metallic trilayers, we predict that the oscillation period of the IEC constant is dramatically changed by hole doping into the LaNiO 3 spacer, while the MR ratio is relatively unaffected.