Gadolinium in lutetium fluoride-an electron paramagnetic resonance study

Gadolinium (Gd3+) in Czochralski-grown lutetium fluoride (LuF3) has been in vestigated by electron paramagnetic resonance (EPR). Detailed analysis of t he EPR angular dependencies reveals that Gd3+ entered substitutionally for LU3+ in monoclinic C-5 site symmetry. The Lu site seems to be more distorte d by the Gd ion as compared to the Y site in YF3. The zero-field splitting of the ground state b(2)(0) is -1.8372 GHz which is more than twice compare d to that of Gd3+ in host crystals of LaF3, in which gadolinium has the sam e co-ordination number. The results of the fine structure analysis are comp ared to a similar study in the iso-structural host YF3. The obtained result s seem to be in contrast to the superposition model. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.