%0 Journal Article
%A Vitova, Tonya
%A Mangold, S.
%A Paulmann, Carsten
%A Gospodinov
%A Marinova
%A Mihailova, Boriana
%T X-ray absorption spectroscopy of Ru-doped relaxor ferroelectrics with a perovskite-type structure
%J Physical review / B
%V 89
%N 14
%@ 1098-0121
%C College Park, Md.
%I APS
%M DESY-2014-02701
%P 144112
%D 2014
%X X-ray absorption near-edge structure and extended x-ray absorption fine structure spectroscopy at the Ru K edge of Ru-doped PbSc0.5Ta0.5O3 (PST-Ru), PbSc0.5Nb0.5O3 (PSN-Ru), and 0.9PbZn1/3Nb2/3O3-0.1PbTiO3 (PZN-0.1PT-Ru) as well as at the Ta L3 edge of PST-Ru and the Nb K edge of PSN-Ru was applied to study the short- and intermediate-range atomic arrangements in perovskite-type (ABO3) relaxor ferroelectrics. The compounds were also analyzed by complementary Raman scattering, visible/near-visible absorption spectroscopy, and synchrotron x-ray single-crystal diffraction. The results show that Ru is octahedrally coordinated in all three relaxor host matrices but the average oxidation state of Ru in PST-Ru and PSN-Ru is ∼4.4, whereas it is ∼3.8 in PZN-0.1PT-Ru. In PbSc0.5B"0.5O3 (B" = Ta, Nb) Ru substitutes for the B" cations in the form of isolated point defects, while in PZN-0.1PT-Ru Ru replaces adjacent A and B sites, forming a chainlike structural species of face-sharing elongated octahedra. Chemical 1:1 B-site order as well as dynamic BO6 tilting is observed around both the Ru dopant and the major B" cation in PST-Ru and PSN-Ru regardless of the fact that according to x-ray diffraction at ambient conditions, the average structure is cubic with weak or no long-range chemical order. Pb cations are off-center displaced from the prototypic cubic A site for all three compounds and in Ru-doped PbSc0.5B"0.5O3 the BO6 tilt angle correlates with the degree of coherent B-Pb distances.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000335228100002
%R 10.1103/PhysRevB.89.144112
%U https://bib-pubdb1.desy.de/record/168874