Fabrication and characterization of La0.7Sr0.3MnO3 sandwich structure separated by （La0.7Sr0.3MnO3）m（BiFeO3）n superlattice

Abstract

The La0.7Sr0.3MnO3 sandwich structure separated by （La0.7Sr0.3MnO3）m（BiFeO3）n superlattices is grown in situ on SrTiO3（001） substrates by RF magnetron sputtering. The X-ray diffraction scans indicate that the films are obviously superlattice structures. The resistivity-temperature curves measured in the case of current perpendicular to the plane geometry show that the films undergo metal-insulator transition at 290 K, which is a little lower than the temperature of single La0.7Sr0.3MnO3 film. When the current is within 0.01—10 mA, the peak resistivity of the （La0.7Sr0.3MnO3）m（BiFeO3）n films decreases with the increasing current.The change rate which is higher than that of single La0.7Sr0.3MnO3 film increases with the increasing thickness of the period films. The current-voltage curves indicate that the conduction mechanism in superlattices is space-charge-limited con-duction and a big bias voltage which is a characteristic of Schottky junction is also found in the current-voltage curves at low temperatures.