Heat capacity enhancement and thermodynamic properties of nanostructured amorphous SiO2

The heat capacity of nanostructured amorphous SiO2 (na-SiO2) has been measured by adiabatic calorimetric method over the temperature range 9-354 K. TG and DSC were also employed to determine the thermal stability. The Tg for the two same grain sizes with different specific surface of na-SiO2 samples...

Full description

Saved in:
Bibliographic Details
Published inJournal of non-crystalline solids Vol. 296; no. 1-2; pp. 139 - 142
Main Authors Wang, Lan, Tan, Zhicheng, Meng, Shuanghe, Druzhinina, Anne, Varushchenko, Raisa A, Li, Guanghai
Format Journal Article
LanguageEnglish
Published 01.12.2001
Online AccessGet full text

Cover

More Information
Summary:The heat capacity of nanostructured amorphous SiO2 (na-SiO2) has been measured by adiabatic calorimetric method over the temperature range 9-354 K. TG and DSC were also employed to determine the thermal stability. The Tg for the two same grain sizes with different specific surface of na-SiO2 samples and one coarse-grained amorphous SiO2 (ca-SiO2) sample were 1377, 1397 and 1320 K, resp. The low temperature experimental results show that there are significant heat capacity (Cp) enhancements among na-SiO2 samples and ca-SiO2. Entropy, enthalpy, Gibbs free energy and Debye temperature were obtained based on the low temperature heat capacity measurement of na-SiO2. The Cp enhancements of na-SiO2 were discussed in terms of configurational and vibrational entropy. 17 refs.
Bibliography:ObjectType-Article-2
SourceType-Scholarly Journals-1
ObjectType-Feature-1
content type line 23
ISSN:0022-3093
DOI:10.1016/S0022-3093(01)00902-4