EXAFS and Mössbauer spectroscopic study of Febearing tetrahedrites

Abstract

AbstractEXAFS and Mössbauer data on synthetic silver-rich tetrahedrite, (Cu, Ag)10+xFe2−xSb4S13, reveal the presence of Fe2+and Fe3+the former occupying trigonal planar sites and the latter tetrahedral sites. There is also a clear relationship between increased silver substitution and an increase in Fe2+. The amount of Fe3+incorporated in the synthetic tetrahedrites is proportional to the excess of Cu+(Cu + Ag > 10 atoms) in the mineral, thus maintaining a charge balance. The iron in the natural tetrahedrites and the tennantite examined is mainly tetrahedrally co-ordinated Fe2+.