LAUSR

Abstract Carrier doping to 3d transition metal oxides was proposed as an effective 3d band-filling control method. The mechanism differs from that previously reported to involve “charge discontinuity at the heterointerface”. The mechanism uses the energy difference between 3d bands beyond the heterointerface, with the relative energy of the O2p band being shared at the heterointerface. To test the proposal, electrical conductivity was investigated at the heterointerface between LaFeO3 and SrTiO3. The LaFeO3/SrTiO3 heterointerface showed a metallic conductivity similar to that observed for a LaAlO3/SrTiO3 heterointerface. However, the sheet resistance of the LaFeO3/SrTiO3 system was larger than that of the previously reported LaAlO3/SrTiO3 system. The dependence of the sheet conductance on the thickness of the LaFeO3 layer also differed from the corresponding dependence of the LaAlO3/SrTiO3 system. These findings suggest it is possible to control the Fe3d6 band-filling of LaFeO3 by retransfer of electrons from the TiO2 layer to the FeO2 layer.