Structural heterogeneity and pressure-relaxation in compressed borosilicate glasses by in situ small angle X-ray scattering.
Structural heterogeneity and pressure-relaxation in compressed borosilicate glasses by in situ small angle X-ray scattering.
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DOI：
10.1063/1.3593399
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发表时间：
2011-05
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通讯作者：
Sindy Reibstein;Lothar Wondraczek;D. Ligny;S. Krolikowski;Sergey Sirotkin;J. Simon;V. Martinez;B. Champagnon
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文献类型：
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作者：
Sindy Reibstein;Lothar Wondraczek;D. Ligny;S. Krolikowski;Sergey Sirotkin;J. Simon;V. Martinez;B. Champagnon
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 p(f) = 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.
