Microstructure modification of amorphous titanium oxide thin films during annealing treatment

Crystalline titanium dioxide, TiO2, photocatalytic films were deposited by reactive r.f. magnetron sputtering on glass substrates without additional external heating. A pure metallic titanium target was sputtered in a mixture of argon and oxygen. The effect of the total pressure and the oxygen partial pressure on the deposition rate, the phase composition, the crystallinity, the surface morphology and the resulting photocatalytic properties was investigated. The films were characterized by X-ray diffraction, scanning electron microscopy and scanning probe microscopy. The photocatalytic activity was evaluated by the measurement of the decomposition of methylene blue under UV irradiation. The results showed that the crystalline anatase, anatase/rutile or rutile films can be successfully deposited on unheated substrate and their formation is dependent on the total pressure and the oxygen partial pressure. A schematic phase diagram was constructed. The surface morphology is strongly influenced by the total pressure and the anatase TiO2 films with a more open surface, a higher surface roughness and a larger surface area are formed at higher total pressures. The anatase films with such surface morphology deposited in the reactive sputtering mode exhibit the best photocatalytic activity.

Effect of total and oxygen partial pressures on structure of photocatalytic TiO2 films sputtered on unheated substrate

Deposition and modification of titanium dioxide thin films by filtered arc deposition

Thin film TiO2 photocatalyst deposited by reactive magnetron sputtering

Structural and optical properties of titanium oxide thin films deposited by filtered arc deposition

Preparation of Rutile TiO_2 Films by RF Magnetron Sputtering

TiO2 films were prepared by rf (1356 MHz) magnetron sputtering using a mixture of Ar and O2 gases At a total pressure of 2 mTorr, 100% rutile TiO2 films were successfully obtained on non heated substrates with rf power of 200 W, while 100% anatase TiO2 films were deposited at a pressure of 20 mTorr Spatial profiles of both emission of excited species and plasma parameters were measured by optical emission spectroscopy (OES) and the Langmuir probe method At a pressure of 2 mTorr, it was found that high-energy electrons are generated at a certain radial position near the cathode surface where the transverse magnetic field is maximum, and the strong localization of plasma was observed It was proven that the energetic species impinging on the growing film are responsible for the formation of the rutile phase even if the substrate is at room temperature

https://iopscience.iop.org/article/10.1143/JJAP.34.4950/pdf

Youichiro Noguchi

Papers

Preparation of Rutile TiO_2 Films by RF Magnetron Sputtering

Preparation of Rutile TiO 2 Films by RF Magnetron Sputtering