TY  - JOUR
AU  - Vitova, Tonya
AU  - Mangold, S.
AU  - Paulmann, Carsten
AU  - Gospodinov
AU  - Marinova
AU  - Mihailova, Boriana
TI  - X-ray absorption spectroscopy of Ru-doped relaxor ferroelectrics with a perovskite-type structure
JO  - Physical review / B
VL  - 89
IS  - 14
SN  - 1098-0121
CY  - College Park, Md.
PB  - APS
M1  - DESY-2014-02701
SP  - 144112
PY  - 2014
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000335228100002
DO  - DOI:10.1103/PhysRevB.89.144112
UR  - https://bib-pubdb1.desy.de/record/168874
ER  -