钙钛矿La_(0.67)Pb_(0.33)MnO_3薄膜的制备及表征  

Fabrication and characterization of perovskite-type La_(0.67)Pb_(0.33)MnO_3 thin film

作　　者：韩立安[1] 杨华平[1] 

机构地区：[1]西安科技大学基础部,陕西西安710054

出　　处：《西安科技大学学报》2007年第1期143-145,151,共4页Journal of Xi’an University of Science and Technology

摘　　要：利用磁控溅射法在单晶LaAlO3(100)衬底上成功的外延生长了La0.67Pb0.33MnO3薄膜。用X射线衍射、原子力和超导量子干涉仪、振动样品磁强计对其进行了表征。结果表明,薄膜为赝立方钙钛矿结构,晶胞参数为a=3.861 nm,具有良好的单晶外延结构和光滑的表面。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。在室温条件下,当H=0.8T时,磁电阻效应非常明显,此现象是由于固有磁电阻效应引起的,并不是低场磁电阻效应引起的。室温下,其矫顽力只有50奥斯特。Using magnetron sputtering method, La0. 67 Pb0. 33 MnO3 thin films have been grown on （100） LaAl03 single-crystal substrates. The thin film was characterized by X ray diffraction, atomic force microscopy, superconducting quantum interference device and vibrating sample magnetoments. The resuits show that the thin film have a pseudo-cubic perovskite structure with the cell parameter a = 3. 861nm, have a good epitaxial direction and smooth surface. The Curie temperature is 345 K, near the Curie temperature, the magnetic property shows a transition from ferromagnetic to paramagnetic. La0.67 Pb0.33 MnO3 thin film indicates a characteristic spin glass from zero-field cooled and field cooled magnetization curve, which is due to strain effects. The thin film have quite a distinctive magnetoresistance effect at the room temperature when the magnetic field is 0.8T, which implies the CMR effect in La0.67 Pb0.33MnO3 films originates only from the intrinsic MR effect instead of low-field magnetoresistance effect. The coercive force of the thin film is only 500e at the room temperature.

关 键 词：薄膜 LA0.67 Pb0.33 MNO3 钙钛矿 表征 

分 类 号：TN29[电子电信—物理电子学]