Abakumov, Artem

Hadermann, Joke

Korthout, Katleen

Meert, Katrien

Morozov, VA

Poelman, Dirk

Smet, Philippe

English

Ghent University Academic Bibliography

Linking the structure and luminescence of R2−xEux(MoO4)3 (R= Gd, Sm; 0≤x≤2) scheelites  K. W. Meert, K. Korthout, D. Poelman and P. F. Smet, LumiLab, Department of Solid State Sciences, , Krijgslaan 281-S1,9000 Gent, Belgium V. A. Morozov, A. M. Abakumov and J. Hadermann, EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium Keywords: Scheelites, Luminescence, EXAFS  Scheelites are ABO4 compounds (A = alkali, alkaline-earth or rare-earth element; B = Mo, W) with the most well-known scheelite being CaWO4. In scheelite related compounds there is a partial substitution of the A and/or B cation and crystals can be aperiodic in 3-dimensional space. Here, the structure and luminescence of monoclinic (α-) and orthorhombic (β´-) R2−xEux(MoO4)3 (R=Gd, Sm, 0≤x≤2) modifications was investigated. The structures were investigated using synchrotron powder X-ray diffraction and transmission electron microscopy. All R2−xEux(MoO4)3 (R= Gd, Sm; 0≤x≤2) phosphors emit intense red light dominated by the 5D0 – 7F2 transition at 616 nm but a change in the multiplet splitting is observed when switching from the monoclinic to the orthorhombic structure. This is a consequence of the change in coordination polyhedron of the luminescent ion from RO8 to RO7 for the α- and β´-modification, respectively.  In addition, extended x-ray absorption fine structure spectroscopy (EXAFS) was applied on the material. This technique allows to investigate the local neighbourhood of ions. In the specific case of the (Sm,Eu)2(MoO4)3 scheelites, it can be used to probe the influence of the presence of Eu or Sm on the geometry and size of the rare earth site in the crystal and to determine site occupancy.    Fig. 1 PL spectra of - (λex=394.5 nm) and β´-Gd1.5Eu0.5(MoO4)3 (λex=395.25 nm) at 10 K.  References 1. M. V. Raskina, V. A. Morozov, B. I. Lazoryak, K.W. Meert, K. Korthout, P. F. Smet, D. Poelman, N.Gauquelin, J. Verbeeck, A.M. Abakumov, J. Hadermann, Crystal Structure and Luminescent Properties of R2−xEux(MoO4)3 (R=Gd, Sm) Red Phosphor, submitted to ??   

Linking the structure and luminescence of R2−xEux(MoO4)3 (R= Gd, Sm; 0≤x≤2) scheelites

https://biblio.ugent.be/publication/5752442/file/5752444

Linking the structure and luminescence of R2−xEux(MoO4)3 (R= Gd, Sm; 0≤x≤2) scheelites

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Ghent University Academic Bibliography