Room-Temperature Ferromagnetism in TiO2 Nanocrystals Synthesized by the Controlled Hydrolysis Procedure.

TiO2 nanocrystals were prepared by a controlled hydrolysis procedure at room temperature. The effect of V-doping, N-doping and V/N codoping on the lattice parameters and magnetic properties of TiO2 nanocrystals was investigated by means of X-ray diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy and vibration sample magnetometry. Doping performed at room temperature causes the expansion of lattice parameters. Undoped and doped TiO2 nanocrystals show room-temperature ferromagnetism. A monotonic correlation between saturation magnetization and the ratio of the lattice parameter c to a (c/a) was observed. Saturation magnetization of TiO2 nanocrystals increases with the value of c/a.