Raman spectra, structural units and durability of nuclear waste glasses with variations in composition and crystallization: Implications for intermediate order in the glass network

The Cr 2 O 3 content influence on the structure of 70 TeO 2·25 B 2 O 3·5 SrO glasses, was investigated by infrared and Raman spectroscopies. The results show that BO 3 and BO 4 are among the main structural units in the investigated glasses, together with TeO 3 and TeO 4 units. The presence of chromium ions located in the glass network is well evidenced in the IR and Raman spectra.

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Raman Spectroscopy and Statistical Analysis of the Silicate Species and Group Connectivity in Cesium Silicate Glass Forming System

International Journal of Spectroscopy ◽

10.1155/2015/572840 ◽

2015 ◽

Vol 2015 ◽

pp. 1-15 ◽

Cited By ~ 7

Author(s):

Armenak Osipov ◽

Leyla Osipova ◽

Rimma Zainullina

Keyword(s):

Experimental Data ◽

Raman Spectroscopy ◽

Statistical Analysis ◽

Raman Spectra ◽

Dynamic Equilibrium ◽

Structural Units ◽

Melt Temperature ◽

Deconvolution Analysis ◽

Glass Forming ◽

Increasing Temperature

The Raman spectra of x%Cs2O-(100 − x)%SiO2 (x=17, 22, 27, 33, and 37 mol%) glasses and melts were measured in the temperature range of 293 to 1553 K. The concentrations of the Qn species were calculated as a function of the composition and temperature based on the deconvolution analysis of the spectra. It was found that a dynamic equilibrium among structural units in the melts with x>17 mol% can be described by disproportionation reaction Q3⇔Q4+Q2. The enthalpy of this reaction was found to be equal to 32 ± 6, 43 ± 8, 56 ± 10, and 52 ± 9 for x=22, 27, 33, and 37 mol%, respectively. The nonideal entropy of mixing (ΔSmix) depends on the melt temperature and increases almost linearly with increasing temperature. The Qn, Q2–Q2, and Qn,ijkl distributions with x ranging from 0 to 55 mol% were modeled using experimental data for the concentrations of the Qn units.

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Investigation on Glasses in Strontium Zinc Borosilicate System as Sealants for Solid Oxide Fuel Cell

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.585.195 ◽

2012 ◽

Vol 585 ◽

pp. 195-199 ◽

Cited By ~ 1

Author(s):

Babita Tiwari ◽

S.C. Gadkari ◽

G.P. Kothiyal

Keyword(s):

Heat Treatment ◽

Glass Ceramics ◽

Glass Network ◽

Solid Solution Phase ◽

Structural Units ◽

Thermal Expansion Coefficients ◽

Expansion Coefficients ◽

Zinc Borosilicate ◽

B2o3 Glass ◽

Quench Method

Glasses in the SrO-ZnO-B2O3-SiO2 (SZBS) system with different additives like V2O5, Cr2O3, TiO2, and Al2O3 have been prepared by melt-quench method. Glasses were subjected to controlled heat treatment for conversion into glass-ceramics. Investigated glasses and glass-ceramics have thermal expansion coefficients (TEC) in the range of 95-120 x 10-7/oC (30-600 oC) which closely match with TEC of other SOFC components. XRD indicates the crystallization of Sr2ZnSi2O7 solid-solution phase in glasses upon heat treatment. Structural studies revealed that mainly Q1 and Q2 silicate structural units are present in the glass network and B2O3 enters in the network as triangular borate (BO3) structural units. Only small fraction of B2O3 enters as tetragonal borate (BO4) structural units at higher concentration of B2O3. Glass network depolymerizes with the addition of additives and concentration of Q1 units increases at the expense of Q2 units. Small addition of V2O5 in SZBS glass is beneficial for increasing TEC and achieving better flowability at lower sealing temperature. Studied SZBS glasses also show good bonding with Crofer-22-APU. Elemental line scans indicate that interdiffusion of Fe, Cr, Sr and Si across interface is responsible for good bonding with Crofer-22-APU. To show suitability of material for high temperature sealing, seals have been prepared and tested for vacuum integrity at 850oC for 500h.

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Nonlinear physical properties of some nonconventional semiconducting Bi–Pb–Ba–O glasses

Journal of Materials Research ◽

10.1557/jmr.1998.0325 ◽

1998 ◽

Vol 13 (8) ◽

pp. 2328-2333

Author(s):

D. K. Modak ◽

G. Banerjee ◽

M. Karar ◽

M. Sadhukhan ◽

A. K. Bera ◽

...

Keyword(s):

Glass Matrix ◽

Glass Network ◽

Nonlinear Behavior ◽

Local Instability ◽

Temperature Dependent ◽

Structural Units ◽

Local Ordering ◽

Fast Quenching ◽

Heat Capacity Anomaly ◽

Glass Compositions

Semiconducting Bi1−xPbxBaO3−δ (or BPB) glasses with x = 0 to 0.8 have been prepared by fast quenching from the melt. Interesting anomalies in the temperature-dependent polaronic conductivity and dielectric constant have been observed in all these glass compositions at temperatures, Tp, varying from 310 to 330 K (depending on Pb concentration). This nonlinear behavior is considered to be associated with the local ordering or the displacements of the BiO3 type pyramidal structural units present in the glass matrix (observed from the infrared spectra of these glasses). This type of ordering/displacement gives rise to a local instability in the glass network structure which is also supported by the observed heat capacity anomaly around the same temperatures Tp.

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On the analysis and prediction of elastic properties in alkali Na2O–B2O3–V2O5 glasses under the substitution of V2O5 by Na2O

Physics and Chemistry of Glasses European Journal of Glass Science and Technology Part B ◽

10.13036/17533562.60.6.09 ◽

2019 ◽

Vol 60 (6) ◽

pp. 213-221

Author(s):

Amin Abd El-Moneim ◽

Hassan Y. Alfifi

Keyword(s):

Elastic Properties ◽

Dissociation Energy ◽

Packing Density ◽

Poisson’S Ratio ◽

Elastic Moduli ◽

Unit Volume ◽

Dominant Role ◽

Glass Network ◽

Poisson's Ratio ◽

Structural Units

In this article, we have continued our recent work(30,42) on the prediction of elastic properties in alkali borovanadate glasses. Changes in the elastic moduli and Poisson’s ratio due to the substitution of V2O5 by Na2O in the ternary alkali Na2O–B2O3–V2O5 glasses have been analysed and predicted on the basis of the theories and approaches that existing in the field. Both the packing density and dissociation energy per unit volume of the glass were evaluated in terms of the basic structural units that constitute the glass network. In addition to this, the theoretical values of elastic moduli and Poisson’s ratio were calculated from the Makishima–Mackenzie’s model and compared with the corresponding experimental values. The results revealed that the concentrations of the basic structural units BO3, BO4, VO5 and VO4 play a dominant role in correcting the anomalous behaviour between experimental elastic moduli and calculated dissociation energy per unit volume. An excellent agreement between the theoretical and experimental elastic moduli was achieved for majority of the samples. The correlation between bulk modulus and the ratio between packing density and mean atomic volume has also been achieved on the basis of Abd El-Moneim and Alfifi’s approaches.

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Raman spectra of synthetic orthophosphates used for nuclear waste management

Acta Crystallographica Section A Foundations of Crystallography ◽

10.1107/s0108767311087459 ◽

2011 ◽

Vol 67 (a1) ◽

pp. C496-C496

Author(s):

H. Schlenz ◽

J. Heuser ◽

S. Schmitz ◽

C. Babelot

Keyword(s):

Waste Management ◽

Raman Spectra ◽

Nuclear Waste ◽

Nuclear Waste Management

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Raman spectra of quasi-binary glasses As2S3−GeS2 doped with Er

Journal of Research in Physics ◽

10.2478/jrp-2013-0003 ◽

2013 ◽

Vol 37 (1) ◽

pp. 33-38

Author(s):

V. B. Petrović ◽

I. O. Gúth ◽

S. R. Lukić-Petrović

Keyword(s):

Raman Spectroscopy ◽

Rare Earth ◽

Raman Spectra ◽

Chalcogenide Glasses ◽

Glass Matrix ◽

Earth Element ◽

Structural Units ◽

Low Intensity ◽

Quasibinary System ◽

Different Origin

Abstract This work is concerned with a study of chalcogenide glasses doped with the rare-earth element erbium. The study was carried out on samples of the quasibinary system As2S3−GeS2 doped with erbium at the concentrations of 0, 0.01, 0.1, 0.5 and 1 at %. Raman spectroscopy was used to identify the presence of particular structural units in the glass matrix. The spectra of all the samples are characterized by an intense peak appearing as a consequence of the stretching of the As-S and Ge-S bonds. Further, several low-intensity peaks of different origin were also registered. These peaks arise due to the stretching of the bonds in the ring S8 and the bonds resulting from the existence of the ethane-type molecules (GeSn) in some of the samples. The peaks in the spectrum of the sample with the highest erbium content are characterized by the peaks that can be attributed to the stretching of the bond Er-S.

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