High-temperature phase transitions and elasticity of silica polymorphs
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- 作者：Dmitry L. Lakshtanov ; Stanislav V. Sinogeikin and Jay D. Bass
- 关键词：Quartz ; Cristobalite ; Elastic constants ; High temperature ; Phase transitions ; Brillouin scattering
- 刊名：Physics and Chemistry of Minerals
- 出版年：2007
- 出版时间：January, 2007
- 年：2007
- 卷：34
- 期：1
- 页码：11-22
- 全文大小：403 KB
- 刊物类别：Earth and Environmental Science
- 刊物主题：Earth sciences
Mineralogy
Crystallography
Geochemistry
Mineral Resources - 出版者：Springer Berlin / Heidelberg
- ISSN：1432-2021
文摘
The single-crystal acoustic velocities of α- and β-quartz were measured by Brillouin spectroscopy to a maximum temperature >1,500°C at room pressure. From these velocities, the single-crystal elastic moduli were calculated up to 1,050°C, exceeding the temperature range of previous measurements by 350°C for the elastic moduli and by 710°C for acoustic velocities. The ordinary refractive index (n o) of α- and β-quartz was measured from room temperature to 800°C. In the temperature interval from ～950 to 1,000°C a subtle change in the temperature derivative of the longitudinal acoustic velocity was observed in platelet geometry for all measured directions. The high-temperature acoustic velocity data may indicate the presence of a second phase, presumably β-cristobalite, that nucleates below 1,000°C.