Structural and vibrational properties of CeO2 nanocrystals

In this paper, we report the synthesis and characterization of CeO2 nanocrystals dispersed into a porous Vycor glass. We analyzed the nanocrystal structural properties using X-ray diffraction, Raman spectroscopy and transmission electron microscopy (TEM). The size of the nanocrystals is controlled via the mass increment only and the matrix plays an important role in controlling the nanocrystal size because it prevents the coalescence process. Coalescence control is attributed to nanocrystal dispersion into the host and to the terminal bonds present in the pores that act as anchors, thus resulting in a low diffusion of the nanocrystals through the porous network. We have determined a Raman frequency dependence on the nanocrystal size which is quite useful for a quick check of the size of CeO, nanocrystals. (c) 2007 Elsevier Ltd. All rights reserved.68462262

Size-controllable synthesis of nanosized-TiO2 anatase using porous Vycor glass as template

In this paper we report the synthesis and characterization of TiO2 nanocrystal dispersed into a porous Vycor glass. We have obtained very small TiO2 nanocrystals in the anatase form. The nanocrystal size is controlled via the mass increment only thus preventing the growth through the coalescence process. The nanocrystal size was monitored through transmission electron microscope and Raman scattering. The coalescence control is attributed due to the obtention of nanocrystals dispersed into the host and to the terminal bonds present in the porous which act as an anchor thus resulting in a low diffusion of the nanocrystals through the porous network.8114114