A low frequency Raman study of fractons in partially densified silica aerogels

被引：2

作者：

Anglaret, E ^{[1
]}

Beurroies, I

Duffours, L

Levelut, C

Foret, M

Delord, P

Woignier, T

Phalippou, J

Pelous, J

机构：

[1] Univ Montpellier 2, Dynam Phases Condensees Grp, Montpellier, France

[2] Univ Montpellier 2, Lab Verres, Montpellier, France

来源：

JOURNAL OF NON-CRYSTALLINE SOLIDS | 1998年 / 225卷 / 1-3期

关键词：

Raman study; aerogels; hydrostatic pressure; densification;

D O I：

10.1016/S0022-3093(98)00323-8

中图分类号：

TQ174 [陶瓷工业]; TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

We report on a low-frequency Raman scattering study of base-catalyzed silica aerogels (BCSA) and partially densified BCSA prepared by heat treatment (HT), hydrostatic pressure (HP) and uniaxial pressure (UP). Low-frequency Raman susceptibility scales with frequency, chi(omega) similar to omega(-phi) within a large range of frequencies whose extent decreases with densification. Changes in the spectra are correlated with densification-induced changes in structure and connectivity of BCSA. phi is a constant independent of density for all as-prepared samples, in agreement with their mutual self-similarity. phi also remains essentially constant for HT samples while it decreases for HP and UP samples. phi values are discussed in terms of fractal and spectral dimensions of the samples in the light of the theoretical predictions of Alexander, Courtens and Vacher (ACV) and recent Brillouin scattering results. (C) 1998 Elsevier Science B.V. All rights reserved.

引用

页码：248 / 253

页数：6

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