Structure and properties of lead silicate glasses and melts

Abstract

To cite this version:Ilyes Ben Kacem, Laurent Gautron, Daniel Coillot, Daniel R. Neuville. Structure and properties of lead silicate glasses and melts. Chemical Geology, Elsevier, 2017, 461, pp.104-114 AbstractViscosity, density and glass transition temperature measurements were performed on the simple PbO-SiO 2 system with increasing PbO content from 5 to 70 mol.%. The results of these analyses have been complemented by spectroscopic studies (Raman & X-Ray Absorption Spectroscopy) in order to link macroscopic properties to structural information at short-and middle-range order. A strong decrease of the viscosity is observed even with the incorporation of 5 mol.% PbO, and this decrease goes on with the increase of PbO content. This effect is confirmed by the continuous decrease of the glass transition temperature with increasing PbO content. Based on our interpretations of Raman spectra, which show similarities to alkali or earth-alkaline-silicate glasses, these effects appear to arise from depolymerization of the silica network. Consequently, lead acts as a network modifier even at low content. Although, it could form PbO 4 tetrahedra when it is present in large quantities, it cannot be asserted that lead acts as a network former at high lead content.Keywords: lead silicate, Raman spectroscopy, Viscosity, glasses, structure of glasses and melts Highlights Lead silicate glasses were made from 95 to 30 mol.% SiO 2 . Pb cation acts as network modifier even above the orthosilicate composition (more than 65 mol.% PbO). Viscosity and deconvolution of all Raman spectra in the PbO-SiO 2 system are presented.2

SiO2-Based Nanostructured Superhydrophobic Film with High Optical Transmittance

“…Low-frequency range (<1200 cm −1 ) of the Raman spectrum contains the bands typical for the siloxane bonds. The band at 139 cm −1 can be attributed to the boson peak of the SiO2 network [16]. The bands at 450 and 559 cm −1 correspond to Si-O-Si symmetric stretching of Q4 and Q3 species, respectively.…”

Influence of barium oxide on glass-forming ability and glass stability of the tellurite–phosphate oxide glasses

“…In the trigonal pyramid structure, there are two bridging oxygen sites and one non-bridging oxygen (NBO) which is a Te = O double bond [5,16,25]. This is a unique structural characteristic of TeO 2 glass, distinct from other network-forming glasses; e.g., silicates, phosphates and germanates in which only the NBO and bridging oxygen exist as a part of the structural unit [5,16,[26][27][28][29]. Modifiers such as BaO and ZnO break the random network of glasses, and the concentration of TeO 3 and TeO 3?d units increases [30].…”

The HXD95: a modified Bassett-type hydrothermal diamond-anvil cell for in situ XRD experiments up to 5 GPa and 1300 K

“…Pb-silicate glasses have unique optical properties that make them suitable for high-end 'crystal glass' tableware, as well as for industrial applications in radiation shielding or in optoelectronic devices (Kohara et al, 2010). A complete structural description of the PbO-SiO 2 system by Raman and X-ray absorption spectroscopies can be found in the work by Ben Kacem et al (2017). These authors showed that the addition of only 5 mol% PbO resulted in a significant decrease of viscosity and that glass transition temperature decreased continuously with increasing PbO contents, concluding that Pb had considerable network-modifying potential even at low concentrations.…”