Startseite Structure of the fluorapatite (100)-water interface by high-resolution X-ray reflectivity
Artikel
Lizenziert
Nicht lizenziert Erfordert eine Authentifizierung

Structure of the fluorapatite (100)-water interface by high-resolution X-ray reflectivity

  • Changyong Park EMAIL logo , Paul Fenter , Zhan Zhang , Likwan Cheng und Neil C. Sturchio
Veröffentlicht/Copyright: 28. März 2015
Veröffentlichen auch Sie bei De Gruyter Brill

Abstract

A complete understanding of the surface chemistry of the apatite-water system requires direct observation of the interfacial structure at the molecular scale. We report results for the structure of the apatite (100)-water interface obtained with high-resolution specular X-ray reflectivity from a natural growth surface of Durango fluorapatite. A uniform termination at the crystallographic unit-cell boundary was determined. An atomistic model of the interfacial structure is compared to the experimental results and optimized through non-linear least-squares fitting in which the structural parameters were selected to be both physically and chemically plausible. The best-fit structure includes a Ca- and/or F-deficient outermost surface, minimal structural relaxations of the near-surface apatite crystal, and the presence of a layered interfacial water structure exhibiting two distinct water layers. The height of the first water layer is 2.64(9) Å relative to the relaxed surface with 3.5(1.3) water molecules per surface unit-cell area (64.9 Å2). A second layer of adsorbed water is found 1.53(5) Å above the first layer, followed by a nearly featureless profile of the bulk liquid water. The layered structure of water is interpreted as being due to hydrogen bonding at the solid-water interface. The interfacial structure shows a strong similarity with the octacalcium phosphate structure projected along a surface normal direction.

Received: 2003-8-15
Accepted: 2004-4-2
Published Online: 2015-3-28
Published in Print: 2004-11-1

© 2015 by Walter de Gruyter Berlin/Boston

Artikel in diesem Heft

  1. First-principle study of polytype structures of 1:1 dioctahedral phyllosilicates
  2. Calorimetry of liquids in the system Na2O-Fe2O3-SiO2
  3. A Mössbauer study of the oxidation state of Fe in silicate melts
  4. Nanometer-scale measurements of Fe3+/ΣFe by electron energy-loss spectroscopy: A cautionary note
  5. The most reduced rock from the moon, Apollo 14 basalt 14053: Its unique features and their origin
  6. Quantitative analysis of ammonium in biotite using infrared spectroscopy
  7. Lizardite-chlorite structural relationships and an inferred high-pressure lizardite polytype
  8. V oxidation state and coordination number in silicate glasses by XAS
  9. Structure of the fluorapatite (100)-water interface by high-resolution X-ray reflectivity
  10. Origin of diffuse superstructure reflections in labuntsovite-group minerals
  11. Isosymmetric structural phase transition of orthoenstatite: Molecular dynamics simulation
  12. Crystal nucleation in hydrous rhyolite: Experimental data applied to classical theory
  13. Investigation of polytypes in lepidolite using electron back-scattered diffraction
  14. Iron partitioning between basaltic melts and clinopyroxene as a function of oxygen fugacity
  15. The synthesis of zeolite-P, Linde Type A, and hydroxysodalite zeolites from paper sludge ash at low temperature (80 °C): Optimal ash-leaching condition for zeolite synthesis
  16. High-pressure viscometry of polymerized silicate melts and limitations of the Eyring equation
  17. Biological control on calcite crystallization: AFM investigation of coccolith polysaccharide function
  18. Order parameter variation through the C2/m-P21/m phase transition in cummingtonite
  19. Arsenate sorption on schwertmannite
  20. Evidence on the structure of synthetic schwertmannite
  21. Crystal-chemical characterization of tourmalines from the English Lake District: Electron-microprobe analyses and Mössbauer spectroscopy
  22. Crystal chemistry and paragenesis of compositionally unique (Al-, Fe-, Nb-, and Zr-rich) titanite from Afrikanda, Russia
  23. Site distribution of Fe2+and Fe3+in the axinite mineral group: New crystal-chemical formula
  24. Epidote-rich talc-kyanite-phengite eclogites, Sulu terrane, eastern China: P-T-fO₂estimates and the significance of the epidote-talc assemblage in eclogite
  25. Quantitative mineralogy of the Yukon River system: Changes with reach and season, and determining sediment provenance
  26. Exsolution of thortveitite, yttrialite, and xenotime during low-temperature recrystallization of zircon from New Caledonia, and their significance for trace element incorporation in zircon
  27. Mineralogical characterization and genesis of hydrothermal Mn oxides from the flank of the Juan the Fuca Ridge
  28. Synchrotron X-ray diffraction study of the structure of shafranovskite, K2Na3(Mn,Fe,Na)4[Si9(O,OH)27](OH)2⋅nH2O, a rare manganese phyllosilicate from the Kola peninsula, Russia
  29. Letter. Coupled cation and oxygen-isotope exchange between alkali feldspar and aqueous chloride solution
Heruntergeladen am 24.9.2025 von https://www.degruyterbrill.com/document/doi/10.2138/am-2004-11-1209/html
Button zum nach oben scrollen