Magnetically tunable properties related with carriers density in self-doped La1-x MnO3 /y wt %Nb- SrTiO3 heteroepitaxial junctions

Abstract

The self-doped La1-x MnO3 (x=0.1 and 0.3) thin films deposited on Nb-doped (wt % y) SrTiO3 (y=0.05 and 0.8) crystals to form heteroepitaxial junctions have been prepared by the pulse laser deposition method. The current-voltage loops of junction were measured at several fixed magnetic fields for the temperature from 10 to 300 K. We have focused on the effects of doping level and annealing time on the magnetically tunable property of the junction. The results show that these junctions have a typical temperature-dependent rectifying characteristics and asymmetrical hysteresis. The magnetically tunable property of the junction was related with the annealing time for the self-doped La1-x MnO3-δ thin film and the doping level in the Nb-doped SrTiO3 (STON) crystal. In the self-doped La0.9 MnO3 /0.05-STON junction annealed at 900 °C for 5 h, the relative ratio of voltage [Vb (0) - Vb (H)] / Vb (0) is about 70% at H=6 T and T=70 K for I=0.1 mA, showing a large magnetically tunable property. These results reveal the great potential of the manganites in configuring artificial devices. © 2010 American Institute of Physics.