La2/3Pb1/3MnO3外延膜的结构及磁电特性研究

通过射频磁控溅射法在单晶LaAlO3(100)衬底上成功的沉积了膜厚为300 nm的La2/3Pb1/3MnO3外延膜。利用X射线衍射仪、原子力和超导量子干涉仪、直流四探针法对其结构、磁电特性进行了系统的研究。结果表明,薄膜为赝立方钙钛矿结构,沿(100)方向择优生长,具有良好的单晶外延结构。居里温度TC=345 K,在居里温度附近,发生铁磁-顺磁转变。此材料呈现出一种典型的自旋玻璃特性,是由于应力造成的。对于顺磁态、自旋玻璃态及铁磁态时其磁矩分布给予了合理的解释。在1 T磁场下,其磁电阻极大值为23.4%。

Preparation and Magnetic Properties of Perovskite- type La2/3-Pb1/3-MnO3 Epitaxial Thin Film

Using RF magnetron sputtering method,300nm La2/3-Pb1/3-MnO3 thin film has been epitaxially grown on(100) LaA103 single-crystal substrates.The structure and the magneto-electrical properties of the thin film are investigated using X ray diffractometer,super-conducting quantum interference device and DC four-probe method.The results exhibit that the thin film with(100) preferred orientation is of a pseudo-cubic perovskite structure and has the good single crystalline.When the Curie temperature is at 335K,nearby the Curie temperature,the magneto-electric properties indicate a transition from ferromagnetic to paramagnetic and exhibit a characteristic of spin glass state,which is due to strain effects.The magnetic rules of paramagnetic state and spin glass state as well as ferromagnetic state are illustrated.The electrical property indicates that the thin film has quite a distinctive magneto-resistance effect which is 23.4% nearby the Curie temperature when the magnetic field is 1T.