Raman study of potassium silicate glasses containing Rb[sup +], Sr[sup 2+], Y[sup 3+], and Zr[sup 4+]: Implications for cation solution mechanisms in multicomponent silicate liquids
- Argonne National Lab., IL (United States)
- Brown Univ., Providence, RI (United States)
The parallel- and perpendicular-polarized Raman spectra of (1 - x) K[sub 2]O [center dot] xM[sup z+][sub 2/z]O [center dot] 4SiO[sub 2]e glasses are presented, where M is one of the Period V cations Rb[sup +], Sr[sup 2+], Y[sup 3+] or Zr[sup 4+]. These compositions represent the equal-oxygen substitution of a Period V cation for K[sup +], which preserves the ratio of nonbridging oxygen (NBO) to Si atoms but not, in general, the ratio of all oxygen to all cations. Rb[sup +] and K[sup +] occupy very similar sites and appear to share the same NBO with virtually no energetic penalty. As the valence of the Period V cation increases, so does the tendency of the cation to form silicate species that are depolymerized relative to the species dominating the structure of the bulk glass. The tendency to form regions comparatively rich in Si-O-Si bonds increases in the same sense. The dominant silicate species are those with 0 or 1 NBO in all glasses. The spectra indicate that K+ shares NBO with Rb[sup +] or Sr[sup 2+], that there is relatively little sharing of NBO by K[sup +] and Y[sup 3+], and that K[sup +] and Zr[sup 4+] share the same NBO in what appears to be a nearly fixed bulk stoichiometric K:Zr ratio of 2:1. The latter provides a mechanism for the substantial increase in ZrO[sub 2] solubility seen in peralkaline liquids. A novel means of expressing homogeneous equilibria in silicate liquids is presented, whereby it is possible to make concrete predictions about the coordination numbers of cations in silicate liquids and to predict how they might be affected by the presence of other cations.
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 6973572
- Journal Information:
- Geochimica et Cosmochimica Acta; (United States), Journal Name: Geochimica et Cosmochimica Acta; (United States) Vol. 58:8; ISSN GCACAK; ISSN 0016-7037
- Country of Publication:
- United States
- Language:
- English
Similar Records
Coordination chemistry of Ti(IV) in silicate glasses and melts: II. Glasses at ambient temperature and pressure
Structure of mixed alkali/alkaline-earth silicate glasses from neutron diffraction and vibrational spectroscopy
Related Subjects
360602 -- Other Materials-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKALI METAL COMPOUNDS
ALKALI METALS
ALKALINE EARTH METALS
CHEMICAL BONDS
COORDINATION NUMBER
ELEMENTS
GLASS
METALS
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
POTASSIUM SILICATES
RAMAN SPECTRA
RUBIDIUM
SILICATES
SILICON COMPOUNDS
SPECTRA
STRONTIUM
TRANSITION ELEMENTS
YTTRIUM
ZIRCONIUM