Electric field dependence of junction magnetoresistance in magnetite/semiconductor heterostructure at room temperature

We have fabricated Fe3O4/p-Si heterojunction using pulsed laser deposition technique and explored its electro-magnetic transport properties. The heterojunction exhibits backward rectifying property at all temperatures, and appraisal of giant junction magnetoresistance (JMR) is observed at room temperature (RT). Conspicuously, the variation and sign change of JMR as a function of electric field is observed at RT. The backward rectifying behavior of the device is ascribed to the highly doped p-type (p(++)) semiconducting nature of Fe3O4, and the origin of electric field (voltage) dependence of magnetoresistance is explained proposing electronic band diagram of Fe3O4/SiO2/p-Si heterojunction. This interesting result may have importance to integrate Si-based magnetoresistance sources in multifunctional spintronic devices. (C) 2015 AIP Publishing LLC.