钙钛矿La2/3Pb1/3MnO3外延膜的制备及磁性

利用磁控溅射法在单晶LaAlO3(100)衬底上成功地外延生长了La2/3Pb1/3MnO3薄膜.用X射线衍射仪、原子力显微镜和超导量子干涉仪、直流四探针法对其进行了表征.结果表明,薄膜为赝立方钙钛矿结构,晶格常数为3.861 nm,晶格失配度为2.1%,具有良好的单晶外延结构和较光滑的表面,且薄膜中晶粒的生长模式是"柱状"模式.居里温度为325 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.在1.OT磁场下,其磁电阻为23.4%.

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

By using magnetron sputtering method,La2/3Pb1/3MnO3 thin films have been epitaxially grown on(100) LaAlO3 single-crystal substrates.The thin film is characterized by X ray diffraction,superconducting quantum interference device and Dc four probe method.The results show that the thin film has a pseudocubic perovskite structure and the good the epitaxial direction.The curie temperature is 325 K.near the curie temperature,the magnetic property shows a transition from ferromagnetic to paramagnetic.The electrical property indicates a transition from metal to semiconductor.La2/3Pb1/3MnO3 thin film exhibits a characteristic spin glass state from zero-field cooled and field cooled magnetization curve,which is due to strain effects.The thin film has quite a distinctive magnetoresistance effect which is 23.4 % near the curie temperature when the magnetic field is 1.0 T.