Heavy metal oxide glasses have been investigated in the following systems: TeO2–PbO–PbCl2, TeO2–ZnO, Ga2O3–PbO–Bi2O3 glasses with low OH concentration were prepared. The influence of the processing conditions on the color, the structure and the optical properties of the prepared samples was also assessed. Mixtures of starting oxides were melted in various reactive conditions using Pt, Au, SiO2 and alumina crucibles. A set of physical measurements including chemical and X-ray analysis, scanning electron microscopy, absorption spectroscopy, ultraviolet and infrared absorption edges and thermo-physical properties, were carried out. Samples were doped with Nd, Pr and Er rare earth ions. Low temperature photoluminescence spectra show the expected rare earth transitions and the broad band emission of the base glass.

Heavy metal oxide glasses: preparation and physical properties

Glass formation has been investigated in binary systems based on antimony oxide as the main glass former: (100 - x)Sb 2 O 3-x WO 3 , (5 < x < 65), (100 - x)Sb 2 O 3-x SbPO 4 , (5 < x < 80) and (100 - x)Sb 2 O 3-x [Sb(PO 3 ) 3 ] n , (10 < x < 40). Ternary systems derived from the Sb 2 O 3 -WO 3 binary glass have also been studied: Sb 2 O 3 -WO 3 -BaF 2 , Sb 2 O 3 -WO 3 -NaF and Sb 2 O 3 -WO 3 -[Sb(PO 3 ) 3 ] n . Glass transition temperature ranges from 280°C to 380°C. It increases as the concentration in tungsten oxide or antimony phosphate increases. Refractive index is larger than 2. Tungsten-containing glasses are yellow in transmission and turn green at the largest WO 3 content. Optical transmission and temperatures of glass transition, T g , onset of the crystallization, T x , and maximum of crystallization, T p , have been measured using differential scanning calorimetry (DSC). These glasses have potential photonic applications.

Antimony oxide based glasses

We have reported the ionic relaxation for different compositions of $x{\mathrm{Ag}}_{2}\mathrm{O}\ensuremath{-}(1\ensuremath{-}x)\mathrm{Te}{\mathrm{O}}_{2}$ conducting glasses in wide temperature and frequency ranges. We have explained the composition dependence of the conductivity and the activation energy in terms of composition-dependent network structure of these glasses. We have compared the results for silver tellurite glasses with those for the alkali (Li,Na) tellurite glasses and observed that the migration of ${\mathrm{Ag}}^{+}$ ions in glasses, in general, appears to be anomalous. We have analyzed the frequency-dependent electrical data in the framework of the power-law conductivity formalism. We have explained the decreasing trend of the relaxation time with increasing ${\mathrm{Ag}}_{2}\mathrm{O}$ content in terms of structural transformation of tellurite network. Interestingly, we have observed that the concentration of mobile Ag ions is less than the concentration of total Ag ions and decreases with the increase of silver oxide content in the compositions, while the conductivity increases. We have shown that the scaling of the conductivity spectra is independent of temperature, but depends on composition.

Dynamics of Ag + ions in binary tellurite glasses

A structural approach of xPbCl2, (1 − x)Sb2O3 glasses, quenched from the melt, is proposed. The crystallization process of the glasses is analyzed and a Raman scattering investigation is reported. The two investigations give valuable information on the structural arrangement of the glass network. Observations within the xPbCl2, (1 − x)Sb2O3 system show variations of local structure and a comparison is made with previously reported data for some Sb or As based glasses.

Structural approach of the (xPbCl2-(1−x)Sb2O3) glass system

The melt-quenching method has been used to fabricate 9Na2O-(30-x) Bi2O3- xMoO3-40B2O3- 20SiO2-1Fe2O3 glass system where x = (0 ≤ x ≤ 15 mol%). The XRD diffractometer procedure was used to check the status of these samples. Inter-ionic distance (Ri) between Mo–Mo, Polaron radius rp, and inter-nuclear distance ri reduce with the Mo content due to reduce of molar volume. The two-photon absorption coefficient TPA increase with the increase of MoO3 this increased connected to Eg. The values of ionicity Ib slightly increase and the covalency of these glasses reduce with a growth in MoO3 content. The XRD patterns of glass-ceramic show (Na2B4O7), B2Si2O5, Na2SiO3, Fe7BSi3O18, and LiBi (MoO4)2. The morphological of the glass-ceramic has been studied by SEM. FT-IR spectroscopic investigations of the glass-ceramic samples were applied to check the characteristic structure. Mass attenuation coefficient of the prepared samples decreased with the energy increase and with the addition of MoO3.

H. Aomi

Papers

New oxyhalide glasses involving Sb2O3

Sur de nouveaux verres oxyfluores a base d'antimoine

On New Oxyfluoride Glasses Based on Antimony.