Defects and impurities in jarosite: A computer simulation study
MetadataShow full item record
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
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.
Showing items related by title, author, creator and subject.
Walker, A.; Woodley, S.; Slater, B.; Wright, Kathleen (2009)We have studied the formation and migration of point defects within the magnesium sub-lattice inforsterite using a combination of empirical and quantum mechanical modelling methodologies. Empiricalmodels based on a ...
Blanchard, M.; Balan, E.; Wright, Kathleen (2009)The structures, infrared active OH stretching modes, and relative energies of OH-defects in ringwoodite(?-Mg2SiO4) have been studied by first-principles calculations based on density functionaltheory (DFT). Two types of ...
Vacancy defect configurations in the metal-organic framework UiO-66: Energetics and electronic structureSvane, K.; Bristow, J.; Gale, Julian; Walsh, A. (2018)Vacancy lattice sites in the metal-organic framework UiO-66 are known to have a profound effect on the material properties. Here we use density functional theory to compare the energies of defect arrangements containing ...