Electron paramagnetic resonance study of gadolinium in Czochralski-grown yttrium fluoride single crystals

Single crystals of YF3 grown by the Czochralski method have been investigat ed by electron paramagnetic resonance (EPR). In this paper we present an EP R analysis of residual Gd3+ impurities. We found that the Gd3+ rare-earth i on substitutes for Y3+ in YF3. Detailed analysis of the EPR spectra allowed us to determine the fine structure parameters of Gd3+ in monoclinic C-5, s ite symmetry. The EPR angular dependence is dominated by the electronic qua drupole tensor; the g-factor is slightly axial. The b(2)(0) parameter found for Gd3+ in YF3 is unexpectedly high when compared to Gd3+ in the hosts of LaF3 structure where the coordination number is the same. The results let us conclude that YF3 is a promising laser host crystal.