scholarly journals Effects of water on the glass transformation temperature of rhyolitic rock melt.

1981 ◽  
Vol 76 (2) ◽  
pp. 49-57 ◽  
Author(s):  
HIROMITSU TANIGUCHI
Keyword(s):  
Transformation Temperature ◽  
Glass Transformation ◽  
Rhyolitic Rock

scholarly journals Thermal properties of Na2O–P2O5–Fe2O3 polyphosphate glasses

2020 ◽  
Vol 142 (1) ◽  
pp. 203-209 ◽  
Author(s):  
Paweł Goj ◽  
Małgorzata Ciecińska ◽  
Magdalena Szumera ◽  
Paweł Stoch
Keyword(s):  
Thermal Properties ◽  
Phosphate Glass ◽  
Transformation Temperature ◽  
Glass Network ◽  
Iron Phosphate ◽  
Phosphate Glasses ◽  
Continuous Change ◽  
Glass Transformation ◽  
Immobilization Techniques ◽  
Iron Phosphate Glasses

Abstract Iron phosphate glasses are materials that can have many applications like durable matrixes in waste immobilization techniques, biomaterials, optoelectronic devices, etc. Their possible usage is related to their glass network and thermal properties. The influence of Na2O content on thermal properties and crystallization ability of iron phosphate glass of base composition 30 Fe2O3–70 P2O5 mol% were studied. Increasing the content of Na2O causes a decrease in transformation temperature and increase in ΔCp. Characteristic temperatures, thermal stability and crystallizing phases were determined. Increasing content of sodium causes depolarization of iron phosphate glass network which causes a continuous change in ΔCp and glass transformation temperature. Discontinuous change in some glass properties suggests structure rebuilding about 30 mol% of Na2O.

Structure, Vibrational Spectra and Related Physical Properties of Various Glasses in the PbO-Bi2O3-GeO2 System

1986 ◽  
Vol 88 ◽  
Author(s):  
J. E. Canale ◽  
R. A. Condrate ◽  
K. Nassau ◽  
B. C. Cornilsen
Keyword(s):  
Molar Volume ◽  
Bismuth Oxide ◽  
Transformation Temperature ◽  
Lead Oxide ◽  
Structural Changes ◽  
Physical Property ◽  
Volume Data ◽  
Dsc Measurements ◽  
Glass Transformation ◽  
High Concentrations

ABSTRACTVibrational spectroscopy and various physical property measurements (density, molar volume and glass transformation temperature) were used to investigate the structural changes that occurred with changes in composition for glasses prepared by standard melting and quenching techniques in the PbO-Bi2O3-GeO2 system. Regions of constant glass transformation temperature (Tg) were noted for these glasses at high GeO2 compositions, as determined from DSC measurements. These results clearly indicated the presence of amorphous phase separation. A model was proposed that could qualitatively interpret both the infrared and Raman spectra, and the molar volume data. At low lead oxide and bismuth oxide concentrations, lead acted primarily as a network modifier while bismuth acted as a mixed network former and modifier. At high concentrations, both lead and bismuth acted as network formers in linking discrete GeO4-units and possibly forming a lead oxide/bismuth oxide portion of the network. The observed results were also interpreted on the basis of Ge-O bonds involving bridged and non-bridged oxygen atoms, and on the basis of a possible change in coordination for germanium from four to six with metal oxide additions.

Ion dynamics in glass-forming systems: II. Conductivity spectra above the glass transformation temperature

1995 ◽  
Vol 71 (4) ◽  
pp. 713-719 ◽  
Author(s):  
C. Cramer ◽  
K. Funke ◽  
M. Buscher ◽  
A. Happe ◽  
T. Saatkamp ◽  
...  
Keyword(s):  
Transformation Temperature ◽  
Ion Dynamics ◽  
Glass Forming ◽  
Glass Transformation ◽  
Conductivity Spectra

Glass transformation temperature and stability of tellurite glasses

2003 ◽  
Vol 18 (2) ◽  
pp. 402-406 ◽  
Author(s):  
Raouf El-Mallawany
Keyword(s):  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Transformation Temperature ◽  
Unit Volume ◽  
Tellurite Glasses ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Glass Transformation ◽  
Glass Series ◽  
Calculated Number

The glass transformation (Tg) and onset crystallization temperatures (Tx) of (100 – x) TeO2–(x)V2O5, (x = 10, 35, and 50 mol%) glasses were measured in the temperature range 300–800 K by differential scanning calorimetry at different heating rates. From the variation of the heating rate, the glass transition activation energy was calculated by different methods. The glass stabilization range S = Tx – Tg was calculated for the whole glass series. Quantitative analysis of the glass transformation temperature was carried out using the calculated number of bonds per unit volume and oxygen packing density.

Thermal and Radiation Effects in the Range of the Glass Transition Temperature Tg

1988 ◽  
Vol 127 ◽  
Author(s):  
G. Malow
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
High Temperatures ◽  
Transformation Temperature ◽  
Radiation Effects ◽  
Waste Form ◽  
Self Heating ◽  
Glass Transformation

Licencing procedures for the disposal of vitrified HLW require that there should be no unforeseen changes in the product properties prior to and after emplacement of the waste. Such changes could occur upon deliberate or accidental self-heating of the glass up to or even beyond the glass transformation temperature, Tg, over extended periods of time. Hence, an evaluation of the consequences of excessively high temperatures in the waste form is necessary.

Preparation and Analysis of Doped TiO2 in the Bi2O3-SiO2-ZnO-B2O3 Low-Melting Sealing Glasses

2012 ◽  
Vol 509 ◽  
pp. 308-313 ◽  
Author(s):  
Qi Bin Gu ◽  
Jia Miao Ni
Keyword(s):  
Metal Oxides ◽  
Chemical Stability ◽  
Glass Surface ◽  
Transformation Temperature ◽  
Softening Temperature ◽  
Glass Transformation ◽  
Ti Content

In this paper, optical, the chemistry stability, and glass transformation, softening temperature were studied on Bi2O3-SiO2-ZnO-B2O3 system glass doped with 2wt.%、4wt.%、6wt.% and 8wt.%TiO2. The results showed that glass surface has no stripes and defects with transmittance between 20%-50%. Moreover, with the increasing of Ti content, the results of the experiments indicated that the metal oxides TiO2 could enhance the glass chemical stability most clearly, and regulate the glass transformation temperature.

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