X-ray diffuse scattering observations for Sr.sub.x./sub.Ba.sub.1-x./sub.Nb.sub.2./sub.O.sub.6./sub. single crystals with x=0.35 and 0.81

0498087 - FZÚ 2019 RIV GB eng J - Journal Article
Pasciak, Marek - Kopecký, Miloš - Kub, Jiří - Fábry, Jan - Dec, J. - Ondrejkovič, Petr - Hlinka, Jiří - Buixaderas, Elena
X-ray diffuse scattering observations for Sr_xBa_1-xNb₂O₆ single crystals with x=0.35 and 0.81.
Phase Transitions. Roč. 91, 9-10 (2018), s. 969-975. ISSN 0141-1594. E-ISSN 1029-0338
R&D Projects: GA ČR GA16-09142S
Institutional support: RVO:68378271
Keywords : relaxor ferroelectrics * disorder * diffuse scattering
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 1.026, year: 2018

In an attempt to contribute to understanding of structure–property relationship in ferroelectric relaxor SrxBa1−xNb2O6, we studied X-ray diffuse scattering for compositions with x = 0.35 and x = 0.81 at room temperature. Within signal-rich reciprocal-space images, features related to (i) local deformation due to chemical inhomogeneity, (ii) incommensurate modulation and (iii) fluctuation of polarization have been identified. There are substantial differences between the two compositions, some of which can be straightforwardly attributed to different states of ferroelectric ordering in these materials. In the Sr-rich composition, we have observed additional features in the form of ⟨110⟩-oriented streaks on hk(n/2) planes. They indicate that transverse correlation of uniaxial polarization is anisotropic. At the same time, the fact that streaks appear also on the superlattice planes raises the question whether the modulation and polarization order parameter are interrelated.

Permanent Link: http://hdl.handle.net/11104/0290505