Infrared Spectroscopy of Composite Materials Based on High-Silica Porous Glasses Activated by Bismuth and Yttrium Ions

Abstract—Composite materials (CMs) based on matrices of high-silica nanoporous glasses (NPGs) activated by bismuth and yttrium ions are synthesized. The CMs are studied by IR spectroscopy (1000–400 cm^–1), depending on the Bi/Y nitrate ratio in the solution (1 : 1 and 10 : 1) and the heat treatment temperature of the CMs (from 470 to 870°C). The method of IR spectroscopy in composites identifies vibrations characteristic of the cubic modification Y₂O₃ and for the monoclinic modification of bismuth oxide (α–Bi₂O₃); for vibrations of Bi–O and Bi–O–Bi bonds, as well as Bi³⁺ cations in [BiO₆] and/or [Bio₃] structural units; and for vibrations of Bi–O–Si bonds, and for Y–O–Y and Y–O bonds. It is established that an increase in the yttrium content in CMs heat-treated at 470 and 870°C, (all other things being equal) leads to the appearance of additional absorption bands at 564, 556, 432, and 424 cm^–1, which may be related to the formation of the cubic phase Y₂O₃.