Preparation and structural properties of new series of mixed-anion compounds: rare earth fluorosulfides

摘要

Rare earth fluorosulfides with the following compositions: LnSF and Ln_2AF_4S_2 have been prepared by solid state routes. These structures can be described as a stacking of fluoride-based slabs ([Ln_2F_2]~(4+) in LnSF and [Ln_2AF_4]~(4+) in Ln_2AF_4S_2) and double layers [S_2]~(4-). The fluoride blocks are related to fluorite-type structure. The relative compactness of the fluoride blocks leads to a relaxation of the Ln-S bond lengths.