Influence of Heat-Treatment Conditions on the Optical Properties of Bismuth-Containing Composites Based on High-Silica Porous Glass

摘要

Bismuth-containing composite materials are synthesized by the impregnation of matrices of thermally modified porous glass (PG) in 0.5 M aqueous solutions of bismuth nitrate followed by heat treatment. The optical density spectra of the obtained materials are studied depending on the heat treatment temperature (400-870 degrees C). When the temperature of the heat treatment is increased, the distribution of bismuth in the samples becomes more homogeneous. The heat treatment in the range of 650 to 870 degrees C leads to the degree of bismuth oxidation changing from Bi3+ to Bi2+ ions with the formation of dimers and clusters of bismuth.