La_(0.67)Sr_(0.33)MnO_3薄膜的外延性及其巨磁电阻效应

THE EPITAXITY OF La0.67Sr0.33MnO3 THIN FILM AND MAGNETORESISTANCE EFFECTS

利用直流溅射法在(001)LaAIO_3基片上生长了外延的La_(I--x)Sr_xMnO_3(x=0.33)薄膜,薄膜为立方晶系的钙钛矿氧化物,晶格常数为a=39.2nm测量了薄膜在零场和外加场中的电阻率和磁阻随温度的变化。随着基片温度的升高。磁阻值在减少;电阻率峰位向高温区移动;溅射温度为650℃的样品磁阻效应最大,磁电阻效应约达30％。

La0.67Sr0.33MnO3epitaxial thin films have been grown on (001)LaAIO3 sub-strates by DC magnetron sputtering methodd. It is proved that the film is approximately as the cubicsystem. The lattice constant is a = 39. 2nm. Temperature dependencies of the re-sistivity in zero field and applied field for the films have been measured. The magnetore-sistance effects are decreased when the substrate temperature goes up. The largest MR ef-fect was found with substrate temperature at 650℃. It is about 30%.