STRUCTURAL-CHANGES AND ELASTIC PROPERTIES IN AEROGELS INVESTIGATED BY BRILLOUIN-SCATTERING

被引：8

作者：

ANGLARET, E ^{[1
]}

PELOUS, J ^{[1
]}

HRUBESH, LH ^{[1
]}

机构：

[1] LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550

来源：

JOURNAL OF NON-CRYSTALLINE SOLIDS | 1995年 / 186卷

关键词：

D O I：

10.1016/0022-3093(95)00075-5

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：

Silica aerogels with different microstructures were synthesized by one-step and two-step process. Acoustic waves in these materials were studied by Brillouin scattering. As expected, propagative phonons are observed for high-density samples. However, for some two-step samples an asymmetric profile of the Brillouin line is found which was not observed in previous investigations. This behaviour is attributed to some relaxation process coupled to the phonons. After an oxidation heat treatment these relaxations disappear. For low-density samples, the crossover to fracton modes is investigated. Values of the sound velocities, v(0), are compared for different series of samples and the data are correlated structural information.

引用

页码：137 / 141

页数：5

共 18 条

[1] FRACTON DIMENSION OF A MUTUALLY SELF-SIMILAR SERIES OF BASE-CATALYZED AEROGELS [J].

ANGLARET, E ;

HASMY, A ;

COURTENS, E ;

PELOUS, J ;

VACHER, R .

JOURNAL OF NON-CRYSTALLINE SOLIDS, 1995, 186 :131-136

[2] LOW-DENSITY SILICA AEROGELS OBSERVED BY HIGH-RESOLUTION ELECTRON-MICROSCOPY [J].

BOURRET, A .

EUROPHYSICS LETTERS, 1988, 6 (08) :731-737

[3] OBSERVATION OF FRACTONS IN SILICA AEROGELS [J].

COURTENS, E ;

VACHER, R ;

PELOUS, J ;

WOIGNIER, T .

EUROPHYSICS LETTERS, 1988, 6 (03) :245-250

[4]

EMMERLING A, 1993, J PHYS PARIS C S, V8, P357

[5]

Fricke J., 1992, J NONCRYST SOLIDS, V145

[6] ULTRASONIC VELOCITY-MEASUREMENTS IN SILICA, CARBON AND ORGANIC AEROGELS [J].

GROSS, J ;

FRICKE, J .

JOURNAL OF NON-CRYSTALLINE SOLIDS, 1992, 145 (1-3) :217-222

[7]

HASMY A, 1994, PHYS REV B, V50, P5006

[8]

LEVELUT C, IN PRESS

[9]

MICHARD F, 1989, J PHYS PARIS C S, V4, P173

[10]

OLIVIER BJ, 1991, J T AM CRYSTALLOGR A, V27, P199

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