Rectifying properties and colossal magnetoresistance in La0.9Hf0.1MnO3/Nb-0.7 wt%-doped SrTiO3 heterojunction

A heterojunction with good rectifying properties in a wide temperature range from 20 K to 300 K was fabricated simply by depositing an as-grown La0.9Hf0.1MnO3 (LHMO) film on a commercial 0.7 wt% Nb-doped SrTiO3 single crystal substrate using pulsed laser deposition technique. The current-voltage behavior of the LHMO/STON is measured under applied magnetic fields varying between 0 and 5 T. The heterojunction shows a remarkable magnetoresistance which depends on both the temperature and bias voltages. The sign of the magnetoresistance as function of temperature at either forward or reverse bias voltage is extensively studied by the filling of electrons in the e(g) and t(2g) band. The good rectifying behaviors, the magnetic tunable properties and the maximum magnetoresistance obtained at room temperature make this simple heterojunction promising for practical applications.