Magnetic field effects on the manganite junction with different electronic processes

A manganite junction with two distinguishable electronic processes has been fabricated and its rectifying properties are experimentally studied. The current-voltage characteristics of the junctions are found to be dominated by leakage current and thermal current under low and high bias voltages, respectively. The responses of these two processes to magnetic field are found to be different, and the magnetoresistance (MR) of the junction arises mainly from the modification of magnetic field to leakage current. Although the MR shows a monotonic decrease with bias voltage (V), the MR-V dependence is different for the two processes. An approximately linear, yet slow, decrease of MR with V is observed for the leakage process, while an exponential reduction for the thermal one. These results show that the electronic processes undergoing in the junction can be identified based on the analysis of the MR-V relations.