摘要
利用金属有机物分解法在非晶石英衬底上成功地制备了具有 (202)择优取向的多晶 La1- x-SrxMnOz薄膜。原子力显微镜观察显示薄膜具有疏松的结构缺陷。在室温下,观察到薄膜磁电阻随外加磁场变化具有优良的线性特征, 10 kOe磁场下,磁电阻值达到 5%。在 77 K低温下,薄膜具有显著的低场磁电阻效应, 2 kOe磁场下的磁电阻值达到 11%。薄膜的电阻-温度关系具有平缓的金属-绝缘体转变,转变温度远低于其居里温度;在 8 kOe磁场下,薄膜的磁电阻随温度下降而单调上升。上述薄膜的磁输运特性与其结构缺陷 (包括晶界及疏松 )有关。
Polycrystalline La1- xSrxMnOz thin films with (202) preferred orientation were successfully synthesized on amorphous quartz substrates by metal- organic decomposition (MOD). Porous structure in the films was revealed by atomic force microscope. Good linearity of magnetotransport property and about 5% magnetoresistance (MR) ratio under 10 kOe field are obtained at room temperature. A large MR ratio of about 11% under 2 kOe field is observed at 77 K, showing an obvious low- field MR effect. The temperature dependence of resistance presents a smooth metal- insulator transition far below the magnetic transition, and the MR monotonically increases with decreasing temperature under 8 kOe field, both of which are related to the structural defects in the films including grain boundaries and porosity.
出处
《功能材料与器件学报》
CAS
CSCD
2001年第2期130-134,共5页
Journal of Functional Materials and Devices