Transport properties of epitaxial Fe–GaN–Fe tunnel junctions on GaAs

Abstract Using an ultra-high vacuum deposition system equipped with an electron cyclotron resonance microwave plasma nitrogen source, epitaxial Fe–GaN–Fe layers were grown on GaAs for the evaluation of GaN as a spin-dependent tunneling barrier. The tunnel junction conductance was strongly temperature dependent. Above 10 K thermionic emission over the barrier was the dominant transport mechanism, while at lower temperature direct tunneling prevailed. At 4 K, the I – V characteristics were non-linear as expected for metal–insulator–metal systems. To date present, spin-dependent tunneling was not observed.