Dense hydrous magnesium silicates, phase D, and superhydrous B: New structural constraints from one- and two-dimensional 29 Si and 1H NMR

Xianyu Xue, Masami Kanzaki, Anton Shatskiy

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

To gain new structural insights into phase D and superhydrous B, two phases of potential mantle water reservoir, we have applied a range of one- (1D) and two-dimensional (2D) 1H and 29Si NMR techniques, as well as Raman spectroscopy, to samples synthesized at 24 GPa and 900-1100 °C. These data have revealed that phase D is characterized by disordered and varying local structures around both Si and H. The 29Si NMR spectra of phase D contain a nearly symmetric, broad peak near-177.7 ppm, attributable to octahedral Si with local structural disorder. The high-resolution 1H CRAMPS spectra of phase D contain a main broad peak near 12.6 ppm with shoulders near 10 and 7 ppm, suggesting a distribution of hydrogen bonding distances. For superhydrous B, our comprehensive 2D 1H and 29Si NMR results have clearly revealed that it contains dissimilar (H1-H2) pairs and one tetrahedral Si site, consistent with space group Pnn2.

Original languageEnglish
Pages (from-to)1099-1111
Number of pages13
JournalAmerican Mineralogist
Volume93
Issue number7
DOIs
Publication statusPublished - Jul 1 2008

Keywords

  • NMR
  • Order/disorder
  • Phase D
  • Raman
  • Space group
  • Superhydrous B

ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology

Fingerprint Dive into the research topics of 'Dense hydrous magnesium silicates, phase D, and superhydrous B: New structural constraints from one- and two-dimensional <sup>29</sup> Si and <sup>1</sup>H NMR'. Together they form a unique fingerprint.

  • Cite this