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Title: Influence of Radiation and Multivalent Cation Additions on Phase Separation and Crystallization of Glass

Abstract

This report presents results of: (1) measurement of valence state ratios of iron in glass, and (2) a study of the effect of iron redox ratio on phase separation behavior in a glass. The redox ratio of iron in two sodium silicate (NS) glasses has been determined using a colorimetric method, Moessbauer analysis, and optical absorption. The experimental procedures were described in a previous report. We found that these three methods gave excellent agreement for the values of the Fe++/Fe+++ (redox ratio) in the glasses. Also, using the results of the colorimetric analysis we were able to find the extinction coefficients for the18.56% NS and the 13% NS glasses. We have utilized the optical absorption data that was taken for purposes of determining redox ratios to provide glass structural information. In particular, it has been suggested that the band centered near 14,500 cm-1 is indicative of Fe2+ - O2- - Fe3+ formation. In addition, the relative band intensities at 10,000 cm-1 and 4,800 cm-1 could give us information as to the environment around the Fe2+ responsible for the 4,800 cm-1 band. The Moessbauer data will provide supporting structural information. For example, the relative number of clustered and free ferric ionsmore » can be computed from the ratio of areas under the doublet and sextet in the liquid He spectra. Also, the change in shift parameter with redox ratio will provide an indication of whether there is an increase or decrease in tetrahedral site symmetry about both ferrous and ferric ions. Finally, the quadrupole splitting parameter provides information regarding the site symmetries about the Fe++ and Fe+++. Currently, we are analyzing the spectral data for these purposes. The Moessbauer work was done in conjunction with colleagues at PNNL, and a manuscript is currently in preparation. The effect of oxidation state of iron on the phase separation of xNa2O {center_dot}(100-x)SiO2 glasses, x = 18.56 and 13, containing 0.5 mole % iron oxide was studied. The oxidation state of iron in the glasses was varied by changing the melting conditions such as melting temperature and melting atmosphere. The oxidation states of the iron ion were determined by the colorimetric method and by the UV-VIS NIR spectrophotometric method, and a comparison was made between the results obtained using these two techniques. Immiscibility temperatures of the glasses were determined by opalescence and clearing methods. The immiscibility temperature of the sodium silicate binary glasses decreased approximately 25 C with the addition of 0.5 mole % Fe2O3. The immiscibility temperature of the doped glasses increased slightly with increasing concentration of Fe2+ ion in the glass. The liquidus temperature of the 18.56 NS2 glass was determined using an X-ray diffraction technique. Approximately 3 grams of glass powder were heated for 4 hours in the temperature region near the liquidus temperature. XRD patterns were obtained from the samples to determine if any crystalline material was present. The heat-treatment temperatures were incremented in 2 C intervals, and the liquidus temperature was taken as the minimum heat-treatment temperature where the crystalline XRD peaks disappeared in the XRD pattern. From this analysis is was determined that the liquidus temperature decreased about 26 C by the addition of 0.5 mole % Fe2O3. The prediction of immiscibility tendency upon the addition of a minor amount of third component was made using models proposed by Tomozawa and Obara and Nakagawa and Izumitani. Tomozawa and Obara's model showed good agreement with the measured immiscibility values.« less

Authors:
; ;
Publication Date:
Research Org.:
University of Arizona (US)
Sponsoring Org.:
USDOE Office of Environmental Management (EM) (US)
OSTI Identifier:
798533
Report Number(s):
DOE ER45670
TRN: US200222%%361
DOE Contract Number:  
FG07-97ER45670
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 9 Aug 2002
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CATIONS; CRYSTALLIZATION; FORECASTING; GLASS; IRON IONS; IRON OXIDES; MELTING; RADIATIONS; SODIUM SILICATES; SYMMETRY; X-RAY DIFFRACTION; RADIATION EFFECT; PHASE SEPARATION, CRYSTALLIZATION

Citation Formats

Weinberg, Michael C, Uhlmann, Donald R, and Smith, Gary L. Influence of Radiation and Multivalent Cation Additions on Phase Separation and Crystallization of Glass. United States: N. p., 2002. Web. doi:10.2172/798533.
Weinberg, Michael C, Uhlmann, Donald R, & Smith, Gary L. Influence of Radiation and Multivalent Cation Additions on Phase Separation and Crystallization of Glass. United States. https://doi.org/10.2172/798533
Weinberg, Michael C, Uhlmann, Donald R, and Smith, Gary L. 2002. "Influence of Radiation and Multivalent Cation Additions on Phase Separation and Crystallization of Glass". United States. https://doi.org/10.2172/798533. https://www.osti.gov/servlets/purl/798533.
@article{osti_798533,
title = {Influence of Radiation and Multivalent Cation Additions on Phase Separation and Crystallization of Glass},
author = {Weinberg, Michael C and Uhlmann, Donald R and Smith, Gary L},
abstractNote = {This report presents results of: (1) measurement of valence state ratios of iron in glass, and (2) a study of the effect of iron redox ratio on phase separation behavior in a glass. The redox ratio of iron in two sodium silicate (NS) glasses has been determined using a colorimetric method, Moessbauer analysis, and optical absorption. The experimental procedures were described in a previous report. We found that these three methods gave excellent agreement for the values of the Fe++/Fe+++ (redox ratio) in the glasses. Also, using the results of the colorimetric analysis we were able to find the extinction coefficients for the18.56% NS and the 13% NS glasses. We have utilized the optical absorption data that was taken for purposes of determining redox ratios to provide glass structural information. In particular, it has been suggested that the band centered near 14,500 cm-1 is indicative of Fe2+ - O2- - Fe3+ formation. In addition, the relative band intensities at 10,000 cm-1 and 4,800 cm-1 could give us information as to the environment around the Fe2+ responsible for the 4,800 cm-1 band. The Moessbauer data will provide supporting structural information. For example, the relative number of clustered and free ferric ions can be computed from the ratio of areas under the doublet and sextet in the liquid He spectra. Also, the change in shift parameter with redox ratio will provide an indication of whether there is an increase or decrease in tetrahedral site symmetry about both ferrous and ferric ions. Finally, the quadrupole splitting parameter provides information regarding the site symmetries about the Fe++ and Fe+++. Currently, we are analyzing the spectral data for these purposes. The Moessbauer work was done in conjunction with colleagues at PNNL, and a manuscript is currently in preparation. The effect of oxidation state of iron on the phase separation of xNa2O {center_dot}(100-x)SiO2 glasses, x = 18.56 and 13, containing 0.5 mole % iron oxide was studied. The oxidation state of iron in the glasses was varied by changing the melting conditions such as melting temperature and melting atmosphere. The oxidation states of the iron ion were determined by the colorimetric method and by the UV-VIS NIR spectrophotometric method, and a comparison was made between the results obtained using these two techniques. Immiscibility temperatures of the glasses were determined by opalescence and clearing methods. The immiscibility temperature of the sodium silicate binary glasses decreased approximately 25 C with the addition of 0.5 mole % Fe2O3. The immiscibility temperature of the doped glasses increased slightly with increasing concentration of Fe2+ ion in the glass. The liquidus temperature of the 18.56 NS2 glass was determined using an X-ray diffraction technique. Approximately 3 grams of glass powder were heated for 4 hours in the temperature region near the liquidus temperature. XRD patterns were obtained from the samples to determine if any crystalline material was present. The heat-treatment temperatures were incremented in 2 C intervals, and the liquidus temperature was taken as the minimum heat-treatment temperature where the crystalline XRD peaks disappeared in the XRD pattern. From this analysis is was determined that the liquidus temperature decreased about 26 C by the addition of 0.5 mole % Fe2O3. The prediction of immiscibility tendency upon the addition of a minor amount of third component was made using models proposed by Tomozawa and Obara and Nakagawa and Izumitani. Tomozawa and Obara's model showed good agreement with the measured immiscibility values.},
doi = {10.2172/798533},
url = {https://www.osti.gov/biblio/798533}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Aug 09 00:00:00 EDT 2002},
month = {Fri Aug 09 00:00:00 EDT 2002}
}