中文摘要：

采用脉冲激光沉积方法在单晶LaAlO_3（100）平衬底和15。倾斜衬底上制备La0.72Ca0.28MnO3薄膜。在镀膜过程中分别采用溶胶－凝胶法和共沉淀法制备靶材。研究不同方法制备的靶材和相应的薄膜的结构、电输运性能和表面形貌。与共沉淀法相比，采用溶胶－凝胶法制备的靶材具有更加均匀的组分和更大的致密度以及晶粒尺寸，因此具有更高的绝缘体－金属转变温度和更大的电阻温度系数。采用溶胶－凝胶靶材制备的薄膜，其晶粒尺寸更均匀、生长质量更好，绝缘体－金属转变温度高20K，激光感生电压也更大。因此，使用溶胶－凝胶方法制备靶材可以大幅提高脉冲激光沉积方法中薄膜的性能。

英文摘要：

La0.72Ca0.28MnO3 thin films were deposited on untilted and 15° tilted LaAlO_3 （100） single crystalline substrates by pulsed laser deposition. The polycrystalline targets used in the deposition process were synthesized by sol-gel and coprecipitation methods, respectively. The structure, electrical transport properties and surface morphology of the targets and films were studied. It is found that, compared with coprecipitation method, the sol-gel target has more homogeneous components and larger density and grain size, thus the higher insulator-metal transition temperature and larger temperature coefficient of resistivity. The thin film prepared by sol-gel target has a uniform grain size and higher quality. The metal-insulator transition temperature is higher and the laser induced voltage signal is larger. Preparing the target by sol-gel method can largely improve the properties of corresponding thin films in pulsed laser deposition process.