Home Effect of chemical environment on the hydrogen-related defect chemistry in wadsleyite
Article
Licensed
Unlicensed Requires Authentication

Effect of chemical environment on the hydrogen-related defect chemistry in wadsleyite

  • Yu Nishihara EMAIL logo , Toru Shinmei and Shun-ichiro Karato
Published/Copyright: April 1, 2015
Become an author with De Gruyter Brill

Abstract

The effect of chemical environment on the hydrogen-related defect chemistry in wadsleyite was investigated using Fourier-transform infrared (FTIR) spectroscopy. Samples were annealed at P = 14-16 GPa and T = 1230-1973 K using Kawai-type multi-anvil apparatus. The effect of oxygen fugacity (fO₂) was investigated using three metal-oxide buffers (Mo-MoO2, Ni-NiO, and Re-ReO2). The effect of water fugacity (fH₂O) was studied using two different capsule assemblies (“nominally dry” and “dry” assemblies). A range of total OH concentration (COH,Total) of studied wadslyeites varies between <50 H/106Si (<3 wt ppm H2O) and 23 000 H/106Si (1400 wt ppm H2O). The observed FTIR spectra were classified into four different classes, i.e., peaks at 3620 (“3620”), 3480 (“3480”), and 3205 cm-1 (“3205”) and the others (Group O), where the Group O includes peaks at 3270, 3330, and 3580 cm−1. The variation in OH concentration corresponding to each peak was analyzed separately. The OH concentrations correspond to “3620,” “3480,” and “3205” were found to be highly dependent on both fH₂O and fO₂₂. Assuming COH,Group O = 2[(2H)xM] (COH,Group O is OH concentration of Group O), present data were analyzed by using thermodynamic model for concentration of hydrogen-related defects. Based on analytical results, OH concentration of “3620” and “3480” was found to be reasonably explained by q = 1/2 and r = 1/12 (q and r are fHO and fO₂ exponents, respectively), whereas that of “3205” was consistent with q = 1/2 and r = -1/12. These results suggest that “3620” and “3480” correspond to HM′ whereas “3205” corresponds to H·, respectively, under the charge neutrality condition of [FeM′] = 2[VM″ ].

Received: 2007-3-26
Accepted: 2007-12-18
Published Online: 2015-4-1
Published in Print: 2008-5-1

© 2015 by Walter de Gruyter Berlin/Boston

Articles in the same Issue

  1. The crystal structure of vurroite, Pb20Sn2(Bi,As)22S54Cl6: OD-character, polytypism, twinning, and modular description
  2. Mineralogy of the Paso Robles soils on Mars
  3. Dingdaohengite-(Ce) from the Bayan Obo REE-Nb-Fe Mine, China: Both a true polymorph of perrierite-(Ce) and a titanic analog at the C1 site of chevkinite subgroup
  4. Thermal equation of state of CaGeO3 perovskite
  5. Quantitative absorbance spectroscopy with unpolarized light: Part I. Physical and mathematical development
  6. Quantitative absorbance spectroscopy with unpolarized light: Part II. Experimental evaluation and development of a protocol for quantitative analysis of mineral IR spectra
  7. Oxide-melt solution calorimetry of selenides: Enthalpy of formation of zinc, cadmium, and lead selenide
  8. Precise dating of biotite in distal volcanic ash: Isolating subtle alteration using 40Ar/39Ar laser incremental heating and electron microprobe techniques
  9. Rationale for the existence of four- and eight-reversals in antigorite
  10. Structural relaxation around substitutional Cr3+ in pyrope garnet
  11. Metasomatic thorite and uraninite inclusions in xenotime and monazite from granitic pegmatites, Hidra anorthosite massif, southwestern Norway: Mechanics and fluid chemistry
  12. Interlayer potassium and its neighboring atoms in micas: Crystal-chemical modeling and XANES spectroscopy
  13. Effect of chemical environment on the hydrogen-related defect chemistry in wadsleyite
  14. Fracture toughness, hardness, and elastic modulus of kyanite investigated by a depth-sensing indentation technique
  15. Crystal chemistry of the natrojarosite-jarosite and natrojarosite-hydronium jarosite solid-solution series: A synthetic study with full Fe site occupancy
  16. A new experimental thin film approach to study mobility and partitioning of elements in grain boundaries: Fe-Mg exchange between olivines mediated by transport through an inert grain boundary
  17. Titanium as a cathodoluminescence activator in alkali feldspars
  18. Biogenic vs. abiogenic magnetite nanoparticles: A XMCD study
  19. Solubility of andradite, Ca3Fe2Si3O12, in a 10 mol% NaCl solution at 800 °C and 10 kbar: Implications for the metasomatic origin of grandite garnet in calc-silicate granulites
  20. A 3D reconstruction of plagioclase crystals in a synthetic basalt
  21. Rudashevskyite, the Fe-dominant analogue of sphalerite, a new mineral: Description and crystal structure
  22. Birchite, a new mineral from Broken Hill, New South Wales, Australia: Description and structure refinement
  23. Crystal structure of synthetic Al4B2O9: A member of the mullite family closely related to boralsilite
  24. Interaction of gypsum with As(V)-bearing aqueous solutions: Surface precipitation of guerinite, sainfeldite, and Ca2NaH(AsO4)2·6H2O, a synthetic arsenate
  25. Jahnsite-(NaFeMg), a new mineral from the Tip Top mine, Custer County, South Dakota: Description and crystal structure
  26. Evidence for anomalously large degree of polymerization in Mg2SiO4 glass and melt
  27. Theoretical infrared absorption coefficient of OH groups in minerals
Downloaded on 28.9.2025 from https://www.degruyterbrill.com/document/doi/10.2138/am.2008.2653/html
Scroll to top button