The mechanism of ferromagnetic ordering in ZrO_x film is investigated by both experimental observation and theoretical calculation.Magnetic measurements reveal that the magnetic properties can be adjusted from diamagnetism to ferromagnetism by varying the oxygen stoichiometry.We find that oxygen-rich defects can be responsible for the observed magnetic properties by taking the measurements of x-ray photoelectron spectroscopy and room temperature photoluminescence spectra.Density functional theory calculations further confirm that the ferromagnetic order is mainly driven by the exchange interaction between the oxygen antisites and the neighboring anion atoms.
TiO2 thin films were fabricated by RF magnetron sputtering on titanium substrates and then implanted with different amounts of carbon. The microstructure, valence states and optical characteristics of each sample were investigated by X-ray diffraction, X-ray photoelectron spectroscopy and UV-vis diffuse reflection spectroscopy. Photoelectric property was evaluated under visible light using a xenon lamp as illuminant. The experimental results indicate that the implanting carbon concentration has a significant infl uence on film's micro structure and element valence states. The dominant valence states of carbon vary as carbon content increases. Carbon ion implantation remarkably enhances the current density and photocatalytic capability of TiO2 thin films. The optimized implanting content is 9.83×1017 ion/cm2, which gives rise to a 150% increased photocurrent and degradation rate.
