The family of oxide glasses is very wide and it is continuously developing. The rapid development of advanced and innovative glasses is under progress. Oxide glasses have a variety of applications in articles for daily use as well as in advanced technological fields such as X-ray protection, fibre glasses, optical instruments and lab glassware. Oxide glasses basically consist of network formers, such as borate, silicate, phosphate, borosilicate, borophosphate, and network modifiers such as alkali, alkaline earth and transition metals. In the present review article, Raman spectroscopy results for the structures of borate, silicate, phosphate, borosilicate, borophosphate, aluminosilicate, phosphosilicate, alumino-borosilicate and tellurite glasses are summarized.

A review of the structures of oxide glasses by Raman spectroscopy

Borate glasses are the technologically important class of glasses and play a significant role in various applications. Borate glasses contain planar BO3 groups as structural units, rather than tetrahedral SiO4 groups. The oxygen atoms are, as in SiO2, again connected to two network-forming atoms, in case of boron. The radial distribution analysis describes the B2O3 glass structure as consisting of boroxol rings, that is, planar rings containing three boron atoms and three oxygen atoms. The network forming of the B2O3 and the SiO4 is affected with the addition of some metal cation additives Pb, Zn, Cd, and so forth. These additives also work as a network modifier and a nucleating agent for crystallization of glass. Therefore, the optical properties of the borate glasses have been changed significantly.

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A Review on Infrared Spectroscopy of Borate Glasses with Effects of Different Additives

Physical, optical, structural and gamma-ray shielding properties of lead sodium borate glasses

Raman and FTIR spectra of iron phosphate glasses containing cerium

Dy 3+ -doped lead phosphate (PbPKANDy: P 2 O 5 +K 2 O+Al 2 O 3 +PbO+Na 2 O+Dy 2 O 3 ) glasses were prepared by melt quenching technique and their optical properties have been studied. Judd-Ofelt parameters have been evaluated for 1.0 mol% Dy 2 O 3 -doped lead phosphate glass and inturn derived radiative properties for excited luminescent levels of Dy 3+ ions. The yellow-to-blue emission intensity ratios and CIE chromaticity coordinates were calculated which have been used to evaluate white light emission as a function of the activator (Dy 3+ ) ion concentration. The observed non-exponential decay nature and quenching of lifetime for higher Dy 3+ ion concentration (≥1.0 mol%) have been attributed due to energy transfer of dipole–dipole type between excited and unexcited Dy 3+ ions. The PbPKANDy glasses exhibit better luminescence properties which are suitable for generation of white light.

Optical properties and generation of white light in Dy3+-doped lead phosphate glasses

Infrared spectra of Fe2O3–PbO–P2O5 glasses

Glasses in the system x PbO·(100− x )P 2 O 5 ( x =25–60 mol%) have been investigated using IR spectroscopy and by means of density and electrical-resistivity measurements. The infrared spectra revealed that for PbO 50 mol% PbO also plays the role of a network former. The greater rate of density increase for PbO>50 mol% is due to the formation of PbO 4 units. The conductivity of these glasses depends mainly on the mobility of Pb 2+ ions. The variation of the electrical conductivity parameters upon changing the composition have been correlated with the structural changes in the glass matrix.

Structure and some physical properties of PbO-P2O5 glasses

IR spectroscopy, density and DC conductivity measurements have been carried out for Fe2O3–P2O5 glasses. Results indicate that the redox ratio of the Fe2+ ions decreases while the density increases with increasing Fe2O3 content. It is suggested that the change of density might be correlated with the change in the relative concentration of FeO4 and FeO6 units. Analysis of the IR spectra reveals that Fe2O3 enters the phosphate matrix in the form of Fe2+ and Fe3+ ions through the formation of P–O–Fe2+ and P–O–Fe3+ bonds at the expense of P–O–P bonds. The conductivity data were analyzed in terms of Mott's model for small polaron hopping. Variation in conductivity is correlated with structural changes that take place upon increasing the Fe2O3 content in the glasses.

Structure and electric conduction of Fe2O3–P2O5 glasses

Density and dc conductivity measurements have been carried out for five groups of Fe 2 O 3 -PbO-P 2 O 5 glasses. There is a linear change in density and molar volume with increasing Fe 2 O 3 content. Analysis of density data revealed that the volumes of the structural units introduced from Fe 2 O 3 and P 2 O 5 are greater than those from PbO. Each of these oxides contributes to the density with a specific factor that depends on the role of PbO in the structure. Conductivity of the studied glasses exhibits polaronic features above certain Fe 2 O 3 content, which is considered as the boundary between ionic and polaronic conduction. In glasses having lower Fe 2 O 3 content iron ions occupy vacancies in the structure and closes pathways for Pb 2+ ions. Above this Fe 2 O 3 concentration hopping of small polarons dominates the conduction process and their contribution increases with increasing the Fe 2 O 3 content. PbO content has a little effect on the polaronic conduction. It is mainly controlled by the ratio of Fe 2 O 3 /P 2 O 5 . The Fe-Fe distance has the main effect on the activation energy and hence the conductivity of the studied glasses.

I. Abbas

Papers

Infrared spectra of Fe2O3–PbO–P2O5 glasses

Structure and some physical properties of PbO-P2O5 glasses

Structure and electric conduction of Fe2O3–P2O5 glasses

Density and dc conductivity of Fe2O3-PbO-P2O5 glasses