Thermal and structural study on densification of rare-earth-doped PbO–SiO2 aerogels

An attempt to prepare Ce- and La-doped SiO2–PbO glasses for applications as scintillators was realised via aerogel route. The synthesis has been optimised in order to obtain large massive samples required for this application. The effect of Pb in the silica matrix as a co-dopant for rare-earths atoms is discussed: in particular, an increase of rare-earth solubility has been observed. Both 207Pb and 29Si magic angle spinning (MAS) NMR were used to investigate local order and connectivity. The densification of aerogels, investigated by means of DSC, TGA, and X-ray powder diffraction (XRPD), led to glass–ceramic samples because concurrent crystallisation occurred.