Deutsche Tagung f ¨ur Forschung mit ... - SNI-Portal

Struktur und Dynamik Poster: Mi., 14:00–16:30 M-P132
Synchrotron X-ray diffraction study of chemical bonds in crystals under
external electric field
Semen Gorfman 1 , Vladimir Tsirelson 2 , Oleg Schmidt 1 , Marcus Schmidt 3 ,
Horst Bormann 3 , Ullrich Pietsch 1
1 University of Siegen, Siegen, Germany – 2 Mendeleev University of Chemical Technology,
Moscow, Russia – 3 Max-Plank Institute for Chemical Physics of Solids, Dresden,
Germany
The physical properties of crystals such as dielectric polarization and piezoelectricity
are well studied on macroscopic level. They are described by the tensors of dielectric
susceptibilities and piezoelectric constants. In most cases their atomistic origin
is not clear. The evaluation of the structural origin of these phenomena requires insitu
measurement of the microscopic structural response under influence of an external
perturbation. One possible experiment of this type is to monitor the change of X-ray
diffraction intensities by a crystal under a permanent external electric field. Because
the effect is small (∆I/I