TEM characterization of Au nano-particles in TiO2 single crystals by ion implantation

Nano-particles of Au embedded in TiO2 (rutile) single crystals have been synthesized by 260 keV Au ion implantation up to a fluence of 5 × 1016 ions/cm2. Cross-sectional and high resolution transmission electron microscopy (TEM) has been utilized to characterize the size and depth distribution as well as the microstructure of Au nano-particles. The size of Au nano-particles varies 1–20 nm in the TiO2 matrix and the maximum particle size increased with the increasing implantation fluence. These large particles gradually moved toward the surface as implantation fluence increases. Most of Au nano-particles have a specific orientation relationship with the original TiO2 matrix in both as-implanted and post-implantation annealed samples, which is: [1 1 0]Au∥[110]TiO2 and (0 0 2)Au∥(2¯2¯0)TiO2, although the implanted regions of TiO2 were entirely amorphized. The influences of dose rate and annealing on the size and distribution of Au nano-particles are also discussed.