• Champagnon, Bernard
• De Ligny, Dominique
• Krolikowski, S.
• Simon, J. P.
• Sirotkin, S.
• Simon, J.-P.
• Reibstein, S.
• Ligny, D. De
• Krolikowski, Sebastian
• Wondraczek, L.
• Martinez, V.

Abstract

International audience ; We report on Brillouin and in situ small angle X-ray scattering (SAXS) analyses of topological heterogeneity in compressed sodium borosilicate glasses. SAXS intensity extrapolated to very low angular regimes, I(q = 0), is related to compressibility. From Brillouin scattering and analyses of the elastic properties of the glass, the Landau-Placzek ratio is determined and taken as a direct reflection of the amplitude of frozen-in density fluctuations. It is demonstrated that with increasing fictive pressure, topological (mid- and long-range) homogeneity of the glass increases significantly. Heating and cooling as well as isothermal scans were performed to follow the evolution of density fluctuations upon pressure recovery. For a sample with a fictive pressure p(f) of 470 MPa, complete recovery to pf = 0.1 MPa was observed to occur close to the glass transition temperature. The values of fictive and apparent fictive temperature, respectively, as obtained via the intersection method from plots of I(q = 0) vs. temperature were found in good agreement with previous calorimetric analyses. Isothermal scans suggest that mid- and long-range recovery govern macroscopic density relaxation. (C) 2011 American Institute of Physics. [doi:10.1063/1.3593399]

Topics

• density
• impedance spectroscopy
• glass
• glass
• Sodium
• glass transition temperature
• small angle x-ray scattering