Titanium valence and coordination in synthetic richterite – Ti-richterite amphiboles. A synchrotron-radiation XAS study
Paris, Eleonora; Mottana, Annibale; Della Ventura, Giancarlο; Robert, Jean-Lοuis
European Journal of Mineralogy Volume 5 Number 3 (1993), p. 455 - 464
published: Jun 14, 1993
manuscript accepted: Jan 28, 1993
manuscript received: Aug 28, 1992
ArtNo. ESP147050503015, Price: 29.00 €
Abstract Synthetic amphiboles of the richterite - Ti-richterite series have been examined by synchrotron X-ray absorption spectroscopy to determine the oxidation state and coordination of Ti in their structure. The Ti K-edge in the amphiboles is displaced to energy values higher than that of Ti metal (4966.0 eV) and consists of several components. In addition the spectra begin with a single and strong pre-edge feature characteristic of Ti4+ in tetrahedral coordination. The different components of the edge are constant in position throughout the series, but vary in shape and intensity. Multiple and single scattering features suggest that Ti4+ in these synthetic amphiboles resides in a single tetrahedral site having = 1.84 Å, probably T(2).