Formation of the high-pressure modification of hydrated talc at 450°C and 4 GPa - In situ diffraction study
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2016-12-01 |
| Journal | Journal of Structural Chemistry |
| Authors | Anna Likhacheva, Sergey V. Rashchenko |
| Institutions | Budker Institute of Nuclear Physics, V.S. Sobolev Institute of Geology and Mineralogy |
| Citations | 1 |
Abstract
Section titled “Abstract”The formation of the high-pressure hydrous phase Mg3Si4O10(OH)2∙xH2O (10 Å phase) through the reaction “talc + water” at 450°C and 4 GPa was studied using diamond anvil cell. The powder diffraction measurements in situ, performed at the Siberian Center of Synchrotron and Terahertz Radiation (SSTRC), were applied to refine the lattice parameters, atomic coordinates and the occupancy of interlayer H2O site in the structure of 10 Å phase at 450°C and 4 GPa. The lattice parameters are a = 5.234(1) Å, b = 9.053(2) Å, c = 10.87(1) Å, β = 99.2(1)°, and V = 508.5(6) Å3 (space group C2/m). The results of Rietveld refinement show the best fit for the trioctahedral mica structure with split position Ow of the interlayer H2O molecule. The half occupancy of the Ow site corresponds to one H2O molecule per formula unit.