Search

Your search keyword '"Skiagite"' showing total 3 results
Start Over Descriptor "Skiagite" Topic majorite
3 results on '"Skiagite"'

1. High-pressure synthesis of skiagite-majorite garnet and investigation of its crystal structure.

Author

ISMAILOVA, LEYLA, BOBROV, ANDREY, BYKOV, MAXIM, BYKOVA, ELENA, CERANTOLA, VALERIO, KANTOR, INNOKENTY, KUPENKO, ILYA, MCCAMMON, CATHERINE, DYADKIN, VADIM, CHERNYSHOV, DMITRY, PASCARELLI, SAKURA, CHUMAKOV, ALEXSANDR, DUBROVINSKAIA, NATALIA, and DUBROVINSKY, LEONID

Subjects
*CHEMICAL synthesis, *GARNET, *CRYSTAL structure, *SINGLE crystals, *X-ray diffraction
Abstract

Skiagite-rich garnet was synthesized as single crystals at 9.5 GPa and 1100 °C using a multi-anvil apparatus. The crystal structure [cubic, space group Ia...d, a = 11.7511(2) Å, V = 1622.69(5) ų, Dcalc = 4.4931 g/cm³] was investigated using single-crystal synchrotron X-ray diffraction. Synchrotron Mössbauer source spectroscopy revealed that Fe2+ and Fe3+ predominantly occupy dodecahedral (X) and octahedral (Y) sites, respectively, as expected for the garnet structure, and confirmed independently using nuclear forward scattering. Single-crystal X-ray diffraction suggests the structural formula of the skiagite-rich garnet to be Fe32+(Fe 0.234(2)2+Fe1.532(1)3+Si0.234(2)4+)(SiO4)3, in agreement with electron microprobe chemical analysis. The formula is consistent with X-ray absorption near-edge structure spectra. The occurrence of Si and Fe2+ in the octahedral Y-site indicates the synthesized garnet to be a solid solution of end-member skiagite with ~23 mol% of the Fe-majorite end-member Fe32+(Fe2+Si4+)(SiO4)3. [ABSTRACT FROM AUTHOR]

Published
2015
Full Text
View/download PDF

2. Sound velocities of skiagite-iron-majorite solid solution to 56 GPa probed by nuclear inelastic scattering

Author

Leonid Dubrovinsky, Ryosuke Sinmyo, Valerio Cerantola, Leyla Ismailova, Ilya Kupenko, Catherine McCammon, Konstantin Glazyrin, Alexander Chumakov, Denis M. Vasiukov, Natalia Dubrovinskaia, Vasiukov, D, Ismailova, L, Kupenko, I, Cerantola, V, Sinmyo, R, Glazyrin, K, Mccammon, C, Chumakov, A, Dubrovinsky, L, and Dubrovinskaia, N

Subjects
Majorite, 010504 meteorology & atmospheric sciences, Mantle transition zone, Inelastic scattering, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Skiagite, Almandine, Geochemistry and Petrology, Sound velocitie, Transition zone, Khoharite, General Materials Science, 0105 earth and related environmental sciences, Grossular, biology, Chemistry, Garnet, biology.organism_classification, Pyrope, Nuclear inelastic scattering, Andradite, visual_art, visual_art.visual_art_medium, engineering, Atomic physics, Solid solution
Abstract

High-pressure experimental data on sound velocities of garnets are used for interpretation of seismological data related to the Earth’s upper mantle and the mantle transition zone. We have carried out a Nuclear Inelastic Scattering study of iron-silicate garnet with skiagite (77 mol%)–iron–majorite composition in a diamond anvil cell up to 56 GPa at room temperature. The determined sound velocities are considerably lower than sound velocities of a number of silicate garnet end-members, such as grossular, pyrope, Mg–majorite, andradite, and almandine. The obtained sound velocities have the following pressure dependencies: V p [km/s] = 7.43(9) + 0.039(4) × P [GPa] and V s [km/s] = 3.56(12) + 0.012(6) × P [GPa]. We estimated sound velocities of pure skiagite and khoharite, and conclude that the presence of the iron–majorite component in skiagite strongly decreases V s . We analysed the influence of Fe3+ on sound velocities of garnet solid solution relevant to the mantle transition zone and consider that it may reduce sound velocities up to 1% relative to compositions with only Fe2+ in the cubic site.

Published
2018

3. High-pressure synthesis of skiagite-majorite garnet and investigation of its crystal structure

Author

Leyla Ismailova, Valerio Cerantola, Vadim Dyadkin, Andrey V. Bobrov, Sakura Pascarelli, Elena Bykova, Maxim Bykov, Catherine McCammon, Natalia Dubrovinskaia, Aleksandr I. Chumakov, Ilya Kupenko, Leonid Dubrovinsky, Innokenty Kantor, Dmitry Chernyshov, Ismailova, L, Bobrov, A, Bykov, M, Bykova, E, Cerantola, V, Kantor, I, Kupenko, I, Mccammon, C, Dyadkin, V, Chernyshov, D, Pascarelli, S, Chumakov, A, Dubrovinskaia, N, and Dubrovinisky, L

Subjects
Majorite, Materials science, Mössbauer spectroscopy, garnet, Structural formula, Electron microprobe, Crystal structure, engineering.material, majorite, Skiagite, XANES, Crystallography, Geophysics, Geochemistry and Petrology, engineering, single-crystal X-ray diffraction, Spectroscopy, nuclear forward scattering, Solid solution
Abstract

Skiagite-rich garnet was synthesized as single crystals at 9.5 GPa and 1100 °C using a multi-anvil apparatus. The crystal structure [cubic, space group Ia 3 d , a = 11.7511(2) A, V = 1622.69(5) A3, D calc = 4.4931 g/cm3] was investigated using single-crystal synchrotron X-ray diffraction. Synchrotron Mossbauer source spectroscopy revealed that Fe2+ and Fe3+ predominantly occupy dodecahedral (X) and octahedral (Y) sites, respectively, as expected for the garnet structure, and confirmed independently using nuclear forward scattering. Single-crystal X-ray diffraction suggests the structural formula of the skiagite-rich garnet to be Fe32+(Fe2+0.234(2)Fe3+1.532(1)Si4+0.234(2))(SiO4)3, in agreement with electron microprobe chemical analysis. The formula is consistent with X-ray absorption near-edge structure spectra. The occurrence of Si and Fe2+ in the octahedral Y-site indicates the synthesized garnet to be a solid solution of end-member skiagite with ~23 mol% of the Fe-majorite end-member Fe32+(Fe2+Si4+)(SiO4)3.

Published
2015

Catalog

Books, media, physical & digital resources
See catalog results