Abstract

When fluorite crystals, such as CaF₂, are doped with trivalent rare earth ions, interstitial fluoride ions are known to provide charge compensation. The fluoride interstitial can exist either in association with a dopant ion, perturbing its electronic state, or in a distant position where the dopant site symmetry becomes cubic. Dimers, as well as higher order clusters, have also been observed.¹

© 1984 Optical Society of America