Effects of Al2O3, B2O3, Na2O, and SiO2 on nepheline formation in borosilicate glasses: chemical and physical correlations

Raman spectroscopy was applied to complex sodium alumino-borosilicate glasses that precipitate nepheline as their primary phase. The main focus was on the Raman band at 850 cm−1 (wavenumber) observed in quenched glasses. Based on the literature, the 850 cm−1 band was assigned to AlIV–O–Si units in which tetrahedral AlIV are substituted for Si in the network, creating [AlO4/2]− anions that are charge-balanced by Na+ cations. The same glasses with various temperature histories were examined with optical microscopy, scanning electron microcopy and transmission electronic microscopy. The results indicated that the 850 cm−1 Raman band was associated with nanocrystals that formed in the melts and were preserved in the quenched samples. The chemistry of these nanocrystals resembled nepheline. Models relating the intensity of the Raman band at 850 cm−1 and the liquidus temperature (TL) to glass composition revealed that a relationship exists between these two properties. An increase in B2O3 and SiO2 decreased the Raman band intensity and the TL, whereas an increase in Al2O3 and Na2O increased both properties. These effects were attributed to the influence of various oxides on the Na+–[AlO4/2]− activity in the melt.

[1]  Weidan Li,et al.  Thermal Stability Study of the Interconnect System with Fluorinated Silicate Glass as IMD Layers , 1997 .

[2]  B. Mysen,et al.  Curve-fitting of Raman spectra of silicate glasses , 1982 .

[3]  D. Virgo,et al.  Three-dimensional network structure of quenched melts (glass) in the systems SiO 2 -NaAlO 2 , SiO 2 -CaAl 2 O 4 and SiO 2 -MgAl 2 O 4 , 1982 .

[4]  R. Howie,et al.  An Introduction to the Rock-Forming Minerals , 1966 .

[5]  W. White,et al.  Raman spectroscopic investigation of the structure of silicate glasses. I. The binary alkali silicates , 1975 .

[6]  T. Yoko,et al.  Structure and Nonlinear Optical Properties of Lanthanide Borate Glasses , 1997 .

[7]  W. Konijnendijk.  The structure of borosilicate glasses , 1975 .

[8]  P. McMillan.  A Raman spectroscopic study of glasses in the system CaO-MgO-SiO 2 , 1984 .

[9]  Liyu Li,et al.  Raman spectroscopic study of gadolinium(III) in sodium-aluminoborosilicate glasses , 2001 .

[10]  Daniel Sykes,et al.  Melt structure in the system nepheline-diopside , 1990 .

[11]  Liyu Li,et al.  Neodymium (III) in Alumino-Borosilicate Glasses , 2000 .

[12]  P. J. Bray,et al.  Change in boron coordination in alkali borate glasses, and mixed alkali effects, as elucidated by NMR , 1989 .

[13]  D. Virgo,et al.  Relations between the anionic structure and viscosity of silicate melts; a Raman spectroscopic study , 1980 .

[14]  D. Tallant,et al.  Raman and 11B Nuclear Magnetic Resonance Spectroscopic Studies of Alkaline-Earth Lanthanoborate Glasses , 1996 .

[15]  John D. Vienna,et al.  Nepheline Precipitation in High-Level Waste Glasses : Compositional Effects and Impact on the Waste Form Acceptability , 1996 .

[16]  D. Tallant,et al.  Polyhedral Arrangements in Lanthanum Aluminoborate Glasses , 2005 .

[17]  D. Dingwell,et al.  Peraluminous viscosity maxima in Na2OAl2O3SiO2 liquids: The role of triclusters in tectosilicate melts , 1997 .

[18]  W. White,et al.  Raman spectroscopic investigation of sodium borosilicate glass structure , 1981 .

[19]  Liyu Li,et al.  Extended electron energy loss fine structure simulation of the local boron environment in sodium aluminoborosilicate glasses containing gadolinium , 2003 .

[20]  B. Mysen,et al.  Relationships between properties and structure of aluminosilicate melts , 1985 .

[21]  Hassan,et al.  Structural changes of B2O3 through the liquid-glass transition range: A Raman-scattering study. , 1992, Physical review. B, Condensed matter.