Atomic level imaging of Au nanocluster dispersed in TiO2 and SrTiO3

Au nanoclusters dispersed in single crystal TiO2 and SrTiO3 have been prepared by ion implantation at 300 and 975 K and subsequent annealing at 1275 K for 10 h. High-resolution transmission electron microscopy and high angle annular-dark-field (HAADF) imaging in an aberration corrected scanning transmission electron microscope (STEM) have been used to characterize the microstructure of the dispersed gold nanoclusters. The results indicate that Au atoms substitute for cations in these systems. Cavities of up to several tens of nanometers are observed in TiO2 and SrTiO3. The nanometer-sized cavities and Au clusters are faceted along the same lattice plane of the matrix, indicating that the interfacial energy (defined by the An cluster and the matrix) and the surface energy of the matrix (defined by the cavity and the matrix) follow a similar trend of change with respect to different lattice planes of the matrix. Published by Elsevier B.V.