Quantitative analysis of hydrogen sites and occupancy in deep mantle hydrous wadsleyite using single crystal neutron diffraction
- Okayama Univ., Misasa (Japan). Inst. for Planetary Materials
- Okayama Univ., Misasa (Japan). Inst. for Planetary Materials; Japan Agency for Marine-Earth Science and Technology, Nankoku (Japan). Kochi Inst. for Core Sample Research
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division. Chemical and Engineering Materials Division
Evidence from seismological and mineralogical studies increasingly indicates that water from the oceans has been transported to the deep earth to form water-bearing dense mantle minerals. Wadsleyite [(Mg, Fe2+)2SiO4] has been identified as one of the most important host minerals incorporating this type of water, which is capable of storing the entire mass of the oceans as a hidden reservoir. To understand the effects of such water on the physical properties and chemical evolution of Earth’s interior, it is essential to determine where in the crystal structure the hydration occurs and which chemical bonds are altered and weakened after hydration. Here, we conduct a neutron time-of-flight single-crystal Laue diffraction study on hydrous wadsleyite. Single crystals were grown under pressure to a size suitable for the experiment and with physical qualities representative of wet, deep mantle conditions. The results of this neutron single crystal diffraction study unambiguously demonstrate the method of hydrogen incorporation into the wadsleyite, which is qualitatively different from that of its denser polymorph, ringwoodite, in the wet mantle. The difference is a vital clue towards understanding why these dense mantle minerals show distinctly different softening behaviours after hydration.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division. Chemical and Engineering Materials Division
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities Division
- Grant/Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1624862
- Journal Information:
- Scientific Reports, Vol. 6, Issue 1; ISSN 2045-2322
- Publisher:
- Nature Publishing GroupCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Quasielastic neutron scattering of brucite to analyse hydrogen transport on the atomic scale
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journal | October 2018 |
A Picture of Disorder in Hydrous Wadsleyite—Under the Combined Microscope of Solid-State NMR Spectroscopy and Ab Initio Random Structure Searching
|
journal | January 2019 |
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