The use of exafs in the study of defect clusters in doped CaF₂

Abstract

The results of a study of the local structural environment of dopant ions in CaF₂ using the EXAFS technique are reported and compared with data for the same systems obtained from neutron diffraction and computer simulation studies. It is shown that the local structure surrounding the dopant ion is different for Er-doped and La-doped CaF₂. The observed fine-structure is compatible with an octahedral cluster of dopant ions and fluoride interstitials, in the case of Er-doped CaF₂, and an interstitial-dopant dimer which has captured an additional fluoride interstitial, in the case of La-doped CaF₂.