(La0.7Sr0.3MnO3)m(BiFeO3)n超晶格间隔的La0.7Sr0.3MnO3三明治结构制备及表征

采用射频磁控溅射的方法在SrTiO₃（001） 基片上制备了（La_0.7Sr_0.3MnO₃）_m（BiFeO₃）_n超晶格间隔的La_0.7Sr_0.3MnO₃三明治结构.X射线衍射分析证明（La_0.7Sr_0.3MnO_{关键词： 超晶格薄膜 电诱导效应 隧道效应}

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

The La_0.7Sr_0.3MnO₃ sandwich structure separated by （La_0.7Sr_0.3MnO₃）_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 La_0.7Sr_0.3MnO₃ film. When the current is within 0.01—10 mA, the peak resistivity of the （La_0.7Sr_0.3MnO₃）_m（BiFeO₃）_n films decreases with the increasing current.The change rate which is higher than that of single La_0.7Sr_0.3MnO₃ 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.