Cerium(III) fluoride
Cerium fluoride, CeF3, is an ionic compound of the rare earth metal cerium and fluorine.
It appears as a mineral in the form of fluocerite-(Ce) - a very rare mineral species related mainly to pegmatites and rarely to oxidation zones of some polymetallic ore deposits. CeF3 may be used as a Faraday rotator material in the visible, near-infrared and mid-infrared spectral range.
Structure
The crystal structure of cerium fluoride is described as the [Lanthanum trifluoride|] or tysonite structure. It contains 9-coordinate cerium ions that adopt an approximately Tricapped [trigonal prismatic molecular geometry|tricapped trigonal prismatic] coordination geometry, although it can be considered 11-coordinate if two more distant fluorides are considered part of the cerium coordination environment. The three crystallographically independent fluoride ions are 3-coordinate and range in geometry from Trigonal [planar molecular geometry|trigonal planar] to pyramidal molecular geometry|pyramidal].| Cerium coordination | Fluorine F1 coordination | Fluorine F2 coordination | Fluorine F3 coordination |