Preparation and characterisation of monolithic Pr-doped silica glasses by a sol–gel method

Pr–Al co-doped silica glasses have been prepared using Pr(NO3)3 6H2O, Al(NO3)3 9H2O and a sol of fumed silica and HNO3 acidified Si(OC2H5)4 as starting materials. The glasses were characterised by density, transmission electron microscope (TEM), EDAX, refractive index, linear shrinkage, absorption and fluorescence spectra. The glasses were also examined in relation to total –OH content with Pr-concentration. Aluminium co-doping modifies the optical properties of the Pr-doped glasses.