Magnetic and electrical properties of Co-Sm thin films deposited by dc magnetron sputtering

We investigated the effects of oxidation on the magnetic and electrical properties of the Co-Sm films as a function of film composition and substrate temperature. Co-Sm films were prepared on Si(100) and quartz glass by dc magnetron sputtering, and were characterized by XRD, TEM, VSM, RBS, and 4-point probe. Amorphous Co-Sm thin films deposited at room temperature showed strong ferromagnetic properties. For the films deposited at elevated substrate temperature, the resistivity and coercivity increased, while the saturation magnetization decreased. These phenomena were mainly due to partial oxidation of the Co-Sm films, which was verified by RBS measurement and high-resolution TEM analysis.