Preparation of TiO2 Nanoparticles by Pulsed Laser Ablation: Ambient Pressure Dependence of Crystallization

Pulsed laser ablation (PLA) with a KrF excimer laser was used to prepare fine particles of titanium dioxide (TiO2). The ablation in an atmosphere of Ar and O2 (5:5) at total pressures of ≥1 Torr led to the formation of TiO2 nanoparticles composed of anatase and rutile structures without any suboxides. The weight fraction of the rutile/anatase crystalline phases was dependent on the pressure of the Ar/O2 gas. The TiO2 nanoparticles had a spherical shape and their size, ranging from 10 and 14 nm, also appeared to be dependent on the ambient pressure.