Sergey Podlozhenov1, Heribert A. Graetsch2, J. Schneider3, Michael Ulex1, M. Wöhlecke1, K. Betzler1
1Fachbereich Physik, Universität Osnabrück, D-49069 Osnabrück, Germany
2Ruhr-Universität Bochum, D-44801 Bochum, Germany
3Ludwig-Maximilians-Universität, D-80333 München, Germany
Tóm tắt
The structure of strontium barium niobate crystals Sr
x
Ba1 − x
Nb2O6 is comprehensively studied in the whole range of the tetragonal tungsten bronze phase (x = 0.32–0.82) using both powder and single-crystal X-ray diffraction measurements. Unit-cell parameters, density, site-occupancy factors and interionic distances show an explicit composition dependence which can be consistently explained using simple model calculations. The temperature dependence of the unit-cell parameters exhibits a remarkable anisotropy in a broad temperature region below the phase transition temperature. This proves that the electrostrictive contribution to the thermal expansion plays an important role in strontium barium niobate.
