Anion exchange of oxygen by sulfur in GeO2-based glasses

Journal of Non-Crystalline Solids, 2005

Homogeneous amorphous films in the GeS 2-GeO 2 system have been deposited by a RF sputtering technique. Optical characterizations has shown that the cutoff wavelength and the linear indices increase with an increase in the S/O ratio. Raman spectroscopy indicates the presence of new modes that can be assigned to intermediate germanium oxysulfide structural units. Photo-sensitivity of the oxysulfide films has been demonstrated for irradiation near the band-gap. Diffraction gratings inscribed using 488 nm exposure displayed a limited diffraction efficiency (≤3%) that weakens with a corresponding decrease in the glass S/O ratio.

Materials Chemistry and Physics, 2006

Germanium-based sulfide glasses in the Ge-Sb-S system have been elaborated and studied. A relationship between the structure, the composition and the linear optical properties of the glass has been established. The effects of the introduction of Sb on the structure using IR and Raman spectroscopies and on the linear refractive index have been discussed. We have shown that the progressive introduction of Sb 2 S 3 in the glass system (1 − x)GeS 2 -xSb 2 S 3 (with x = 0.10, 0.20, 0.40, 0.62 and 0.80) decreases the number of GeS 4 units in the glass network. As results, the glass transition temperature, the Vicker's microhardness and the stability of the glass against crystallization decrease dramatically. An increase in the density and the linear refractive index as well as shift of the absorption bandgap to infrared have also been observed. Similar behavior has been observed for the glasses of composition Ge 0.23 Sb y S 0.77−y with an increase of y, except in the material's Vicker's microhardness, which increases with an increasing Sb content. This latter result indicates that the microhardness also depends on Sb 2 S 3 content but seems to be more sensitive to GeS 2 content variation.

Journal of alloys and compounds, 2005

Optical Materials, 2017

Glasses based on Sb 2 O 3 make one of the major classes of heavy metal oxide glasses. This paper concerns two antimonite glasses, 88Sb 2 O 3-10Na 2 O-2Bi 2 O 3 (SNB2) and 60Sb 2 O 3-20WO 3-19Na 2 O-1Bi 2 O 3 (SWNB1), doped with 0.25 mol% Er 2 O 3. Bulk samples have been prepared and their absorption and fluorescence spectra have been recorded. Differential scanning calorimeter (DSC) measurements emphasize a thermal stability range DT > 100 C that expresses a good stability against devitrification. Both FTIR and Raman spectra provide information on the structural organization of the glasses. The maximum phonon energies are 700 cm À1 and 920 cm À1 for SNB2 and SWNB1 glasses, respectively. The spectroscopic analysis of the absorption and emission properties of the Er 3þ ions in the SNB2 and SWNB1 glasses has been performed. The Judd-Ofelt theory has been applied to interpret the local environment of the Er 3þ ion site and covalency of the EreO bond, but also to determine the radiative lifetime (t r) for 4 I 13/2 / 4 I 15/2 emission transition. The emission cross-sections for the 4 I 13/2 / 4 I 15/2 transition (1528 nm) were calculated using McCumber and Füchtbauer-Ladenburg theories. We discuss the potential application of these glasses.

International Journal of Applied Glass Science, 2011

Bulk glasses having the compositions As 42 S 58 , As 36 Sb 6 S 58 , and As 36 Ge 6 S 58 have been irradiated at 800 nm using a femtosecond-pulsed laser to determine the relationship between composition and photo-response. Localized variation in the glass volume (photo-expansion) has been determined through interferometric measurements of surface exposures, whereas induced refractive index change (photo-darkening) was determined from the diffraction efficiency of subsurface direct-written phase gratings. To understand the compositional dependence of the photo-response, the linear and nonlinear optical properties and structure of the unexposed glasses have been compared. The ablation threshold is shown to be controlled by variation of the nonlinear absorption, related to shifts of the absorption band gap with exchange of As by Ge or Sb. Changes in the unexposed network structure show that partial replacement of As by Ge or Sb induces an increased number of As-As bonding defects in the glass, particularly in the form of As 4 S 4 molecular units which become polymerized into the network, impacting the photo-modification process. The Ge was found to induce an increase in the ablation threshold, and enhance both photodarkening and photo-expansion effects, whereas Sb was shown to decrease ablation threshold and inhibit photo-darkening while enhancing photo-expansion. *jdm047@clemson.edu

Journal of Non-Crystalline Solids, 2005

Germanate and phosphosilicate glasses made in oxygen surplus conditions were studied by Raman and optical reflection methods. We found that the optical reflection spectra of the germanate glasses are quite similar to the one those of a GeO 2 crystal with the a-quartz structure. The reflection of phosphosilicate glasses is very close to silica glass-related spectra. Hence, the determining influence of the tetrahedral structure on reflection spectra is revealed. The Raman spectra of germanate samples are similar to those reported the one known in the literature. Octahedral entities, namely bands similar to stishovite vibration modes, were difficult to detect in phosphosilicate glasses through Raman spectroscopy.

Photonic Fiber and Crystal Devices: Advances in Materials and Innovations in Device Applications VII, 2013

Colorless sulfide glasses can be obtained by selecting appropriately the composition within the Ga 2 S 3 -GeS 2 -CsCl pseudo-ternary glass system. The addition of electronegative chlorine ions into the sulfide glassy network results in a widening of its optical bandgap without altering its infrared transparency. Glasses transparent from the near UV (380 nm) up to the middle infrared (11.5 µm) are thus achievable. Such extended infrared transmission for a colorless glass is the widest among the known heavy metal oxide and fluoride glasses, e.g. fluoroindate glasses are transparent from 350 nm up to 8-9 µm. We present in this work our recent progress on the preparation of this chloro-sulfide glass of high optical quality. Efforts have been devoted in a first step to reduce the content of extrinsic impurities such as OH, SH and H 2 O. In a second step, protective coatings have been deposited on polished glass samples to improve their chemical durability and assess their potential for practical applications. Large improvement of both optical quality, in terms of transmission spectrum flattening, and chemical durability were achieved. Finally, the high thermal stability against crystallization of this glass shows a high potential for lens molding and applications in multispectral imaging.

Journal of Optoelectronics and Advanced Materials

Antimony glass formation commonly requires conventional glass former such as oxides of silicon, germanium, boron or phosphorus or halides such as PbCl 2 , ZnCl 2 or ZnBr 2 . Recently, a new family of glasses based on the binary systems Sb 2 O 3 -M 2 O (M=Li, Na and K) are reported. Ternary glasses synthesized in vitreous carbon and silicate crucibles were obtained in the combination Sb 2 O 3 -Na 2 O-(PbO or MoO 3 ). Characteristics temperatures of these glasses have been measured using differential thermal analysis (DSC). Glass transition temperature, T g , ranges from 539 to 555 K and the thermal stability range (T x -T g ) lies between 31 and 95 K for binary glasses in the Sb 2 O 3 -MoO 3 . The incorporation of alkali oxides Na 2 O in ternary systems Sb 2 O 3 -Na 2 O-(PbO or MoO 3 ) gives large vitreous area and enhances the stability of antimony glasses. Samples are red in binary Sb 2 O 3 -MoO 3 and turn yellow by the addition of the alkali oxide. These glasses are opaque to UV light since they absorb radiation near 380 nm. Elastics moduli of these glasses were determined by the pulse-echo ultrasonic propagation. These glasses suggested having potential application as low phonon energy glasses for infrared transmission and hosts for rare earth ion in active devices.

Journal of Non-Crystalline Solids, 2008

Four glasses of the SiO 2-GeO 2 binary system have been synthesized via a sol-gel route followed by a heat treatment and a quench. Glass structure has been determined by Ge K-edge X-ray absorption spectroscopy (XAS) at low temperature and Raman spectroscopy. These mixed glasses present a continuous random network of interconnected GeO 4 and SiO 4 tetrahedra, with GeO 4 tetrahedra similar to the GeO 4 units in GeO 2 glass and continuous compositional variations from GeO 2-rich regions to SiO 2-rich regions. Such a random mixture is consistent with physical properties of these binary glasses as well as with the chemical dependence of their polyamorphism at high pressure. This EXAFS-derived mean Ge-O-Si angles are close to the Ge-O-Ge mean angle in GeO 2 glass, 134°and 130°, respectively. This misfit with the Si-O-Si angles might explain the ease of formation of isolated and pair defects centers, which are suspected to be at the origin of photo-induced modifications of optical properties in Ge-bearing SiO 2 glasses.

Journal of non- …, 2001

Glass formation has been investigated in binary systems based on antimony oxide as the main glass former: 100 À xSb 2 O 3 ±xWO 3 , 5 < x < 65, 100 À xSb 2 O 3 ±xSbPO 4 , 5 < x < 80 and 100 À xSb 2 O 3 ±xSbPO 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 ±SbPO 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 dierential scanning calorimetry (DSC). These glasses have potential photonic applications. Ó (M. Poulain). 0022-3093/01/$ -see front matter Ó 2001 Elsevier Science B.V. All rights reserved. PII: S 0 0 2 2 -3 0 9 3 ( 0 1 ) 0 0 3 8 8 -X