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Structure and crystal chemistry of Phase G, A new hydrous magnesium silicate synthesized at 22 GPa and 1050°C
Author(s) -
Kudoh Y.,
Nagase T.,
Mizohata H.,
Ohtani E.,
Sasaki S.,
Tanaka M.
Publication year - 1997
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/97gl00875
Subject(s) - stishovite , silicate , crystal structure , crystallography , magnesium , monochromator , crystal (programming language) , crystal chemistry , phase (matter) , chemistry , materials science , analytical chemistry (journal) , mineralogy , metallurgy , quartz , optoelectronics , wavelength , organic chemistry , chromatography , computer science , programming language
A single crystal of phase G, Mg 1.24 Si 1.76 H 2.48 O 6 synthesized at conditions of 1050°C and 22 GPa, using a multi‐anvil apparatus was studied at the Photon Factory BL‐10A beamline at the National Laboratory for High Energy Physics, Tukuba, Japan. With a (111) Si double‐crystal monochromator and a single crystal measuring 47 × 35 × 12 µm, intensities of 95 independent reflections were collected with sin θ/λ <0.72 Å −1 and Io >1.5 σ Io at a wave length of 0.6990 Å. The unit cell parameters obtained through the refinement of 23 reflections are: Trigonal, a=4.790 (3) Å, c=4.344 (3) Å, V=86.3 (2) ų. The result of structure analysis in space group P1m (No. 162) indicates that the structure of phase G has close structural similarity to that of stishovite,SiO 2 . The calculated density of phase G is 3.43 g/cm³, which is larger than any other known dense hydrous magnesium silicate, suggesting that phase G might be stable even under lower mantle conditions.