Effect of applied magnetic field on the rectifying characteristics in self-doped La0.9MnO3∕0.8wt%Nb–SrTiO3 heteroepitaxial junctions

The epitaxial self-doped La0.9MnO3 thin film was deposited on a 0.8wt%Nb-doped SrTiO3 substrate by pulse laser deposition method to form a bilayer p-n junction with an area of 8mm2. The isothermal current-voltage loops measured from 10to380K with an interval of 10K in applied magnetic fields up to 7T show typical temperature-dependent rectifying characteristic and asymmetrical hysteresis. The effect of magnetic field on the rectifying property is very small for the temperature above 150K and a strong asymmetrical effect on the rectifying property below 150K. In the low temperature region, although the diffusive voltage Vd is not affected by the applied magnetic field, the breakdown voltage Vb decreases with the increasing of magnetic field. At 10K, the relative ratio of voltage [Vb(0)−Vb(7T)]∕Vb(0) is about 14%, showing a magnetically tunable property. These results reveal the great potential of the manganites in configuring artificial devices.