XANES and EXAFS of Crystals

The quantitative analysis of the X-Ray absorption near edge structure (XANES) and extended X-Ray absorption fine structure (EXAFS) of ferroelectrics perovskite crystals is performed by means of the modified full multiple scattering method. The K-absorption spectra of Ti atom in XTiO3 (X=Ca, Pb, Sr) crystals are found to be significantly modified by displacement of the absorbing Ti atom from the instantaneous symmetrical center. This displacement is responsible for the ferroelectricity in the perovskite structure crystals. The polarization effects in the XENES/EXAFS spectra of XTiO3, V2O5 and TiO2 are analyzed. At present the extended theoretical approach and its numerical realization based on the full multiple scattering theory in combination with continuum photoelectron wave functions computed for each center with subsequent matching of solutions obtained for different centers is under development.

Cooperations: Prof. Dr. R.V. Vedrinskii (Rostov State University, Russia)
Status: renewed