Structure of PbOBi2O3Ga2O3 glasses

TLDR: In this article, the structure of PbOBiO1.5 glasses has been investigated by IR and Raman spectroscopy, and the peak deconvolution was made on Raman spectrum of the glasses.

Abstract: The structure of PbOBiO1.5GaO1.5 glasses has been investigated by IR and Raman spectroscopy. An infrared absorption band involving four-coordinated Ga3+ ions was observed at about 610–650 cm−1. The peak of this band shifts toward higher wavenumbers with increasing GaO1.5 content, indicating that covalency of GaO bond increases with increasing GaO1.5 content. The peak deconvolution was made on Raman spectra of the glasses. The Raman bands at about 130 cm−1, 400 cm−1, 550 cm−1 and 650 cm−1, obtained by deconvolution, have been assigned to PbO or BiO, GaOPb or GaOBi, GaOGa, and GaOnon-bridging vibrations, respectively. The presence of 550 cm−1- and 650 cm−1-band indicates that Ga3+ ions are coordinated by four oxygens. The much higher peak wavenumber of the 550 cm−1-band in the spectrum of BiO1.5GaO1.5 glass compared with that in the spectrum of PbOGaO1.5 glass is attributed to the much higher ionic field strength of Bi3+ ion compared with that of Pb2+ ion. The fraction of non-bridging oxygens in GaO4 tetrahedra decreases with increasing PbO and BiO1.5 contents. It is assumed that most Pb2+ and Bi3+ ions are network formers.