Synthesis and spectral-optical properties of composite materials based on high-silica porous glasses doped by iodides of silver and erbium

Abstract

Composite materials (CMs) doped by iodides of silver and erbium were synthesized on the base of the thermally modified high-silica porous glasses (PGs) with small additions of P2O5 and fluoride ions. CMs were manufactured by two-stage impregnation of the PGs first with AgNO3 aqueous solution (with or without Er(NO3)3), next in the halide salt (0.6 M KI) aqueous solution. Then the samples of composites were heat treated at the temperatures from 120 to 870°C up to their sintering and closing of the pores. The structure of composites was studied by X-ray powder diffraction (XRD) technique. According to XRD data the CMs doped by iodides of silver and erbium contain the AgI phase. Spectral-optical properties of CMs were investigated by UV-VIS-NIR spectroscopy. Optical density spectra in UV-VIS region have the bands corresponded with the absorption of silver molecular clusters. Peaks at 377, 448, 450–453, 485, 611–622, 647, 668–684 nm answered to the absorption of erbium ions were found. According to NIR transmission spectra, bands caused by the absorption of Si–OH, B–OH and Na–OH groups are found.