Crystal fields and microscopic local structures of some trigonal symmetry centres in fluorite crystals doped with trivalent rare-earth ions
Year: 1992
Type: article
Abstract: Semi-empirical effective charge calculations were made of crystal field effects and the corresponding energy level splittings for NNN-F - compensated centres in a number of RE 3+ : fluorite structure systems. While the results obtained confirm that such centres were indeed observed in a number of experimental investigations of these dopant: lattice systems, in at least one instance (the B centre in the Er 3+ :CaF 2 system) such identification appears to be untenable. Model reconstructions were also made of local lattice distortions in the centres in the Eu 3+ :SrF 2 and Er 3+ :SrF 2 systems. The two centres are structurally related but the corresponding local distortions appear to be qualitatively different, this result is discussed in the context of other recent work in the field. Finally, the procedure developed was used to improve the phenomenological calculation of B q k values for the trigonal entre in the Eu 3+ :BaF 2 system, demonstrating its utility in such applications by significantly improving final fit quality.
Authors: K Lesniak, F S Richardson
Institutions: Institute of Physics, Polish Academy of Sciences
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2030190720