A spectroscopic comparison of samarium-doped LiYF4 and KY3F10

Laser selective excitation and fluorescence has been performed on LiYF4 and KY3F10 doped with samarium ions. In LiYF4, a single, tetragonal symmetry center associated with isovalent substitution of Sm3+ with lattice yttrium ions is present. By contrast, three Sm2+ centres and a single, tetragonal symmetry Sm3+ center are detected in KY3F10. This complex defect distribution is tentatively explained by the existence of charge-compensating F- vacancies. (C) 2000 Elsevier Science B.V. All rights reserved.