Local atomic structure of niobates and titanates from X-ray absorption spectroscopic data Conference Paper


Author(s): Vedrinskiǐ, Rostislav V; Kraǐzman, V. L; Lemeshko, Mikhail P; Nazarenko, Elena S; Novakovich, Alexander A; Reznichenko, Larisa A; Fokin, Vladimir N; Shuvaeva, Victoria A
Title: Local atomic structure of niobates and titanates from X-ray absorption spectroscopic data
Affiliation
Abstract: The local atomic structure of PbTiO3, BaTiO3, and KNbO3 perovskite-type crystals and K x Na1 − x NbO3 solid solutions in different phases is investigated using the angular dependence of the pre-edge structure of the Ti and Nb K X-ray absorption spectra and the EXAFS data. In noncubic phases, a considerable deviation of the local structure from the structure determined from diffraction data is observed only for the tetragonal phase of the BaTiO3 crystal. It is revealed that, in the cubic phase of niobates, the niobium atoms are characterized by significant displacements from the centrosymmetric positions along the threefold axes, so that they are close in the magnitude and the direction to the displacements in the low-temperatures rhombohedral phases.
Keywords: Temperature; EDGE FINE-STRUCTURE; PHASE-TRANSITIONS; POLARIZED XAFS; KNBO3
Conference Title: CoPoF: 18th All-Russia Conference on Physics of Ferroelectrics (VKS-XVIII)
Volume: 51
Issue 7
Conference Dates: June 9-14, 2008
Conference Location: St Petersburg, Russia
ISBN: 1063-7834
Publisher: Springer  
Date Published: 2009-07-12
Start Page: 1394
End Page: 1398
Sponsor: This study was supported by the Russian Foundation for Basic Research (project no. 070200796a).
DOI: 10.1134/S106378340907018X
Open access: no