Room temperature ferromagnetism of N-doped TiO2 nanowires

• Room temperature ferromagnetic pure and N-doped TiO2 nanowires were synthesized by low temperature hydrothermal method.
• XANES and XRD measurements show that N was doped into TiO2 host after annealing in NH3.
• Pure and N-doped TiO2 nanowires with ~20–30 nm diameters were obtained.
• N-doping enhances the coercive field and saturation magnetization.

The structural and magnetic characterization of pure and N-doped TiO2 nanowires prepared by hydrothermal method was reported. The X-ray absorption near edge structure and X-ray powder diffraction measurements show that N was doped into TiO2 host after annealing in NH3. It is found that doping with N has no effect on the anatase structure of TiO2 nanowires and N related secondary phase is not formed. Magnetization studies reveal that the doped and undoped TiO2 exhibited room temperature ferromagnetism and that saturation magnetization increased with N-doping. Thus, the results indicate the oxygen vacancies and crystallinity play a crucial role in room temperature ferromagnetism of TiO2 nanowires.