Magnetoresistance and surface properties with deposition condition for La-Sr-Mn-O thin films

Polycrystalline La-Sr-Mn-O thin films were grown through RF magnetron sputtering on Si(100) substrates. The conditions for the deposition of the La-Sr-Mn-O thin films were 0, 20, 40, 60 and 80% partial oxygen pressures of the buffer gas, an RF magnetron sputtering power of 2.46 W/cm(2) and a substrate temperature of room temperature. After the deposition, all the films were annealed in the air for 3 hours at 800 degreesC. The crystal structure, the chemical composition, the microstructure, the magnetic properties and the low-field magnetoresistance of the La-Sr-Mn-O films were studied using X-ray diffraction, Rutherford back-scattering spectroscopy, atomic force microscopy, and a vibrating sample magnetometer. The crystal structure of the LSMO thin films was found to be a pseudo-cubic perovskite. As the partial oxygen pressure increased, particle size and root mean square roughness decreased while saturation magnetization and the low-field magnetoresistance increased. 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.