An investigation of the origin of junction magnetoresistance in La0.7Sr0.3MnO3/SiO2/p-Si heterostructures

A detail experimental investigation on magnetic field-dependent electronic transport across p-silicon (Si)/La0.7Sr0.3MnO3 (LSMO) junction in which the LSMO and silicon are separated by different thin interfacial silicon dioxide (SiO2) layers through in situ fabrication has been reported here. All LSMO/SiO2/Si heterostructures exhibit diode-like behaviour at all temperatures. The ideality factor, reverse saturation current, series resistances and turn-on voltages have been estimated for all the heterojunctions at different operating temperatures. The current-voltage characteristics at all temperatures conclusively show the reasonably high sensitivity of the junction under magnetic field showing reasonably high junction magnetoresistance (JMR ∼ 56% at 120 K). The JMR is positive and strongly depends on temperature and applied forward bias voltages. It is also found that the JMR depends upon the leakage current which is generated due to defects present in the oxide and interfacial layer of such heterostructures.