Target effects on electrical properties and laser induced voltages of La0.72Ca0.28MnO3 thin films prepared by pulsed laser deposition

La0.72Ca0.28MnO3 thin films were deposited on untilted and 15° tilted LaAlO3 (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.