Physics and Chemistry of Minerals

, Volume 21, Issue 8, pp 510–515

Pressure-induced coordination change of Ti in silicate glass: a XANES study


  • E. Paris
    • Dipartimento di Scienze della TerraUniversita' di Camerino
  • D. B. Dingwell
    • Bayerisches Geoinstitut, Universität Bayreuth
  • F. A. Seifert
    • Bayerisches Geoinstitut, Universität Bayreuth
  • A. Mottana
    • Dipartimento di Scienze GeologicheTerza Universita' di Roma
  • C. Romano
    • Bayerisches Geoinstitut, Universität Bayreuth

DOI: 10.1007/BF00203925

Cite this article as:
Paris, E., Dingwell, D.B., Seifert, F.A. et al. Phys Chem Minerals (1994) 21: 510. doi:10.1007/BF00203925


The effect of pressure on titanium coordination in glasses, with composition K2TiSi4O11, quenched isobarically from liquids equilibrated at high pressure (5, 10, 15, 20, 25, 30 kbar respectively) and T=1600° C has been investigated by X-ray absorption spectroscopy (XAS). The XANES spectra collected at the Ti K-edge clearly show a variation with pressure that is related to changes in the geometrical environment around the Ti atoms. By comparison with spectra of standard materials, the XANES spectra of the glasses suggest a relatively low average coordination number (near 5) in samples quenched at low pressure and a higher coordination number (near 6) in samples quenched from the highest pressure. The combination of XANES data with density and compressibility measurements supports the idea that a mixture of 6- and lower coordinated (4- and/ or 5-coordinated) Ti geometries are present in the 1 bar glass, and an increasing proportion of 6-coordinated Ti occurs in the glasses synthesized at progressively higher pressures.

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© Springer-Verlag 1994