Journal
HIGH PRESSURE RESEARCH
Volume 28, Issue 4, Pages 641-650Publisher
TAYLOR & FRANCIS LTD
DOI: 10.1080/08957950802510091
Keywords
amorphous SiO2; -quartz; coesite; high pressure; silicon-hydroxy group
Categories
Funding
- National Natural Foundation of China [30370306, 10373022, 10673034]
Ask authors/readers for more resources
The crystallization of amorphous SiO2 powder with free water and silicon-hydroxy group (Si-OH) was investigated in the range of 0-4.2GPa and 150-1200C. The samples were detected by X-ray diffraction, transmission electron microscopy, thermogravimetry and differential thermal analysis, Raman and Fourier transform-infrared spectroscopy. The results show that amorphous SiO2 can transform to cristobalite at 1000C under room pressure. Under high pressure, amorphous SiO2 can quickly transform into single-phase coesite at lower temperature, and the P-T boundary of the crystallization products of mat1 (-quartz and coesite) has been successfully obtained. Through comparing the crystallization products from amorphous SiO2 materials with the same grain size containing different forms of water under high pressure and high temperature, it is found for the first time that the synthesis of coesite can be quickened by virtue of Si-OH in the amorphous SiO2 at lower temperature. The single-phase coesite has been synthesized from amorphous SiO2 with Si-OH under 4.2GPa and 190C for 30min, and 190C is the lowest synthesis temperature of coesite so far.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available