Current-voltage characteristics of phase separated La0.5Ca0.5MnO3/Nb-SrTiO3 p-n junction and magnetic tunability

Abstract

The authors report the current-voltage characteristics of La0.5Ca0.5MnO3/Nb-SrTiO3 p-n junction. This junction shows remarkable thermal hysteresis, giant negative magnetoresistance (MR), remarkable differences of MR for the zero field cooling and field cooling processes, and memory effect of magnetic field. Magnetic force microscopy studies provide direct evidence of magnetic inhomogeneity in La0.5Ca0.5MnO3 film. These intriguing behaviors of our p-n junction can be explained by the phase separation in La0.5Ca0.5MnO3. This work demonstrates the principle of harnessing phase separation for highly tunable device applications. (C) 2008 American Institute of Physics.