7004
J. Phys. Chem. C 2007, 111, 7004-7010
Influence of Surface Coating on Physical Properties of TiO2/Eu3+ Nanocrystals Pushpal Ghosh and Amitava Patra* Department of Materials Science & Centre for AdVanced Materials, Indian Association for the CultiVation of Science, Kolkata 700 032, India ReceiVed: February 10, 2007; In Final Form: March 21, 2007
The sol-emulsion-gel method is used for the preparation of Eu2O3-doped and -coated TiO2 nanocrystals. Here, we report the control of the crystal phase composition and crystallite size as a function of the temperature of heating and surface coating. A significantly higher anatase phase (100%) has been obtained at 800 °C heated sample, and this anatase phase is stable up to 22 nm size. Due to surface coating of TiO2 nanocrystals by Eu2O3, we obtained 27% anatase phase at 1000 °C heated sample, which is new observation in this study. The lattice volume decreases with decreasing the particle size for anatase particle and a nonlinear size dependency of lattice parameters is obtained at size
