Preparation, structure and ferromagnetic properties of the nanocrystalline Ti1-xMnxO2 thin films grown by radio frequency magnetron co-sputtering

This paper reported that the Mn-doped TiO2 films were prepared by radio frequency (RF) magnetron co-sputtering. X-ray diffraction measurements indicate that the samples are easy to form the rutile structure, and the sizes of the crystal grains grow big and big as the Mn concentration increases. X-ray photoemission spectroscopy measurements and high resolution transmission electron microscope photographs confirm that the manganese ions have been effectively doped into the TiO2 crystal when the Mn concentration is lower than 21%. The magnetic property measurements show that the Ti1-xMnxO2 (x = 0.21) films are ferromagnetic at room temperature, and the saturation magnetization, coercivity, and saturation field are 16.0emu/cm3, 167.5 × 80A/m and 3740 × 80A/m at room temperature, respectively. The room-temperature ferromagnetism of the films can be attributed to the new rutile Ti1-xMnxO2 structure formed by the substitution of Mn4+ for Ti4+ into the TiO2 crystal lattice, and could be explained by O vacancy (VO)-enhanced ferromagnetism model