Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5398737 | Journal of Luminescence | 2015 | 4 Pages |
Abstract
Eu3+ substituted YOF and vernier-phase YnOnâ1Fn+2 (n=6, 7) phosphors, which are rhombohedral and orthorhombic structures, respectively, were prepared using a flux-assisted reaction at different temperatures. Stoichiometric and nonstoichiometric yttrium oxyfluoride phases were identified by examination of the indexed peak positions in the X-ray diffraction patterns of the resultant phosphors; however, Y6O5F8 and Y7O6F9 lattice structures in vernier phases were indistinguishable by this method. To identify the vernier phases, the photoluminescence excitation and emission spectra peaks assigned to charge-transfer bands and f-f transitions of Eu3+ ions in YnOnâ1Fn+2 host with the YOF were monitored. The YnOnâ1Fn+2 vernier phases were indicated by the O2â(Fâ)-Eu3+ charge-transfer bands and the site symmetry of Eu3+ emission assigned by 5D0â7F1, 7F2 transitions, and were classified as centrosymmetric Y6O5F8 and noncentrosymmetic Y7O6F9 structures. The critical distances (Rc) in both Y1âxEuxOF and Y6(1âx)Eu6xO5F8 (x=0.001-0.1) lattice structures were calculated by observation of quenching of the relative intensity in the Eu3+ activated red emission.
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Physical and Theoretical Chemistry
Authors
Sangmoon Park,