Magnetoresistive Properties of Manganite-Based Heterojunctions

Hole-doped $La_{2/3}Ba_{1/3}MnO_{3}$ (LBaMO), $La_{2/3}Ca_{1/3}MnO_{3}$ (LCaMO) and $La_{2/3}Ce_{1/3}MnO_{3}$ (LCeMO) thin films were grown heteroepitaxially on 0.1 wt.% Nb-doped $SrTiO_{3}(100)$ (STON) substrates by magnetron sputtering. The prepared LBaMO/STON, LCaMO/STON, LCeMO/STON heterostructures demonstrated nonlinear rectifying current-voltage characteristics. Negative magnetorestance values have been indicated at low bias, meanwhile bias-dependent magnetoresistance has been measured at positive bias voltage values U > U_d where U_d is the interfacial potential, corresponding to a steep current increase at a forward bias.