%0 Journal Article
%A Huittinen, N.
%A Arinicheva, Y.
%A Kowalski, Piotr
%A Vinograd, Victor
%A Neumeier, Stefan
%A Bosbach, D.
%T Probing structural homogeneity of La$_{1-x}$Gd$_{x}$PO$_{4}$ monazite-type solid solutions by combined spectroscopic and computational studies
%J Journal of nuclear materials
%V 486
%@ 0022-3115
%C Amsterdam [u.a.]
%I Elsevier Science
%M FZJ-2017-00893
%P 148 - 157
%D 2017
%X Here we study the homogeneity of Eu3+-doped La1-xGdxPO4 (x = 0, 0.11, 0.33, 0.55, 0.75, 0.92, 1) monazite-type solid solutions by a combination of Raman and time-resolved laser fluorescence spectroscopies (TRLFS) with complementary quasi-random structure-based atomistic modeling studies. For the intermediate La0.45Gd0.55PO4 composition we detected a significant broadening of the Raman bands corresponding to the lattice vibrations of the LnO9 polyhedron, indicating much stronger distortion of the lanthanide cation site than the PO4 tetrahedron. A distortion of the crystal lattice around the dopant site was also confirmed in our TRLFS measurements of Eu3+ doped samples, where both the half width (FWHM) of the excitation peaks and the 7F2/7F1 ratio derived from the emission spectra increase for intermediate solid-solution compositions. The observed variation in FWHM correlates well with the simulated distribution of Eu···O bond distances within the investigated monazites. The combined results imply that homogenous Eu3+-doped La1-xGdxPO4 monazite-type solid solutions are formed over the entire composition range, which is of importance in the context of using these ceramics for immobilization of radionuclides.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000397373600017
%R 10.1016/j.jnucmat.2017.01.024
%U https://juser.fz-juelich.de/record/826675