ISSN:
1432-2021
Keywords:
Key words XANES
;
Full multiple scattering calculation
;
Garnet
;
Ytterbium
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
Abstract We present an X-ray absorption near-edge structure study performed at the Yb LI- and LIII-edges on synthetic pyrope (Mg3Al2Si3O12) and grossular (Ca3Al2Si3O12) garnets containing about 1% wt of Yb. For the first time Yb L-edge XANES spectra are analyzed by full multiple scattering theory using clusters of different sizes and different final-state potentials. A comparison between experimental spectra and model calculations indicates that Yb3+ enters the dodecahedral X-site in both pyrope and grossular, in agreement with the results of an EXAFS study. Based on the present results, the charge balancing substitution mechanism required by the replacement of divalent Mg and Ca cations with trivalent Yb3+ is discussed in terms of vacancies in dodecahedral sites surrounding the central Yb3+ absorber.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002690050244
Permalink