Cerium(III) fluoride explained

Cerium(III) fluoride (or cerium trifluoride), 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.^{[1] [2]} CeF₃ may be used as a Faraday rotator material in the visible, near-infrared and mid-infrared spectral range.^{[3] [4]}

Structure

The crystal structure of cerium(III) fluoride is described as the or tysonite structure.^[5] It contains 9-coordinate cerium ions that adopt an approximately 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 to pyramidal.

Notes and References

1. Web site: Fluocerite-(Ce).
2. Web site: List of Minerals. 21 March 2011.
3. Vojna . David . Yasuhara . Ryo . Slezák . Ondřej . Mužík . Jiří . Lucianetti . Antonio . Mocek . Tomáš . Verdet constant dispersion of CeF3 in the visible and near-infrared spectral range . Optical Engineering . 2017 . 56 . 6 . 067105 . 10.1117/1.oe.56.6.067105 . 2017OptEn..56f7105V . 125990210 .
4. Vojna . David . Slezák . Ondřej . Yasuhara . Ryo . Furuse . Hiroaki . Lucianetti . Antonio . Mocek . Tomáš . Faraday Rotation of Dy2O3, CeF3 and Y3Fe5O12 at the Mid-Infrared Wavelengths . Materials . 2020 . 13 . 23 . 5324 . 10.3390/ma13235324 . 33255447 . 7727863 . 2020Mate...13.5324V . free .
5. Book: A. F. . Wells . Structural Inorganic Chemistry . 5th . 1984 . Oxford University Press . 978-0-19-965763-6 . 420–421 .
6. A powder neutron diffraction study of lanthanum and cerium trifluorides . A. K. . Cheetham . Anthony Cheetham . B. E. F. . Fender . H. . Fuess . A. F. . Wright . . 1976 . 32 . 94–97 . 10.1107/S0567740876002380.