Defects and impurities in jarosite: A computer simulation study

Smith, Adrian M. L. and Hudson-Edwards, Karen A. and Dubbin, William E. and Wright, Kate. 2006. Defects and impurities in jarosite: A computer simulation study. Applied Geochemistry. 21 (8): pp. 1251-1258.

Source Title

Applied Geochemistry

DOI

10.1016/j.apgeochem.2006.06.002

Faculty

Department of Applied Chemistry

Division of Engineering, Science and Computing

Faculty of Science

Remarks

NOTICE: this is the author’s version of a work that was accepted for publication in Applied Geochemistry. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Applied Geochemistry, Volume 21, Issue 8, August 2006, pp. 1251–1258, http://dx.doi.org/10.1016/j.apgeochem.2006.06.002

URI

http://hdl.handle.net/20.500.11937/5148

Collection

Curtin Research Publications

Abstract

Computer modelling techniques involving a rigid ion model have been used to investigate the defect structure and impurity site preferences in end-member K-jarosite. Calculated intrinsic vacancy energies show that the K2SO4 neutral cluster, with an energy per species of 1.34 eV, will be the most common defect in the pure phase. Defect reactions leading to vacancies on the Fe site have high energies, in excess of 4.0 eV per species, and are thus unlikely to occur in great numbers. However, the calculations show that divalent metal cations can be incorporated onto the Fe site via solution reactions with oxides leading to the formation of goethite. Calculated solution reactions are exothermic and thus predicted to be highly favourable. At K sites substitutions occur in the order Cd > Zn > Cu, but will be limited due to endothermic solution energies and structural considerations.