title: The temperature dependence for the third shell's Fourier-peak of Nb-EXAFS in KNbO3 as additional source of information on the local atomic structure.
abstract: The information on the structure of tetragonal KNbO3 is extracted from the temperature dependence of the third shell's Fourier-peak of Nb-EXAFS. It is shown that this dependence can be explained by two effects: 1) rigid rotations of the O6-octahedron and 2) increase of the third shell's DW-parameter. However, diffraction data on the temperature dependence of the DW-parameter permit us to conclude that the last effect only is sufficient and the O6-octahedron rotation doesn't occur in the high-temperature phases of KNbO3. Using EXAFS it is revealed that in the neighboring cells Nb-atoms are parallel shifted closely to [211] direction in tetragonal phase.
authors.affiliation: Department of Physics, Rostov University, Rostov-on-Don, Russia. bugaev@rnd.runnet.ru
authors.forename: L A
authors.initials: LA
authors.lastname: Bugaev
authors.forename: V A
authors.initials: VA
authors.lastname: Shuvaeva
authors.forename: K N
authors.initials: KN
authors.lastname: Zhuchkov
authors.forename: E B
authors.initials: EB
authors.lastname: Rusakova
authors.forename: R V
authors.initials: RV
authors.lastname: Vedrinskii