Ferromagnetic oxide Schottky diode of (Fe, Mn)3O4/Nb:SrTiO3 heterostructure with strongly correlated electrons

Ferromagnetic (Fe,Mn)3O4/band semiconductor- Nb:SrTiO3 Schottky barrier diode was prepared and their electrical properties and electronic structure were investigated. I–V characteristics of the Schottky barrier diode are tunable via design of the effective Coulomb gap in (Fe2.5Mn0.5)O4 ferromagnetic oxide layer, in comparison to Fe3O4. The resulting (Fe2.5Mn0.5)O4/Nb:SrTiO3 contacts exhibit superior rectifying characteristics even at room temperature. According to the enhanced thermionic emission theory, the carrier spin polarization of (Fe2.5Mn0.5)O4 was estimated at ∼0.8 at 100 K and ∼0.7 at 200 K.