Crystal chemistry of mimetite, Pb10(AsO4)6Cl1.48O0.26, and finnemanite, Pb10(AsO3)6Cl2
Klooster, Wim T.
Pramana, Stevin S.
White, Timothy John
Date of Issue2008
School of Materials Science and Engineering
The crystal chemistries of synthetic mimetite, Pb10(As5+O4)6(Cl2-xOx/2), a neutral apatite, and finnemanite, Pb10(As3+O3)6Cl2, a reduced apatite, were characterized using a combination of X-ray powder diffraction, neutron diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. Both phases conform to hexagonal P63/m symmetry; however, the temperature-driven transformation of clinomimetite to mimetite described earlier was not confirmed. The average mimetite structure is best described through the introduction of partially occupied oxygen sites. A better understanding of the mixed arsenic speciation in apatites can guide the formulation of waste form ceramics and improve models of long-term durability after landfill disposal.
Acta crystallographica section B structural science
© 2008 International Union of Crystallography. This paper was published in Acta Crystallographica Section B Structural Science and is made available as an electronic reprint (preprint) with permission of International Union of Crystallography. The paper can be found at: [DOI: http://dx.doi.org/10.1107/S0108768107066402]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.