On December 14 at 14:00 at the conference room on the 2nd floor of the UL ISSP, Ķengaraga iela 8, Nobuo Nakajima (Hiroshima University) will give a talk entitled “Pre-edge features in the Ti K-edge XANES of perovskite titanates”.
Interpretations of pre-edge structures in the X-ray absorption spectra of 3d transition compounds have been in a long debate since the advent of synchrotron radiation sources: quadrupole (E2) or dipole (E1) transitions. Besides the origin of the optical process, the pre-edge structures contain various information related to material function. The dielectric properties of perovskite titanates are discussed quite often. We observed local ferroelectricity in SrTiO
3 under UV irradiation or by lattice distortion in thin films. Recently, we have succeeded to observe dynamic response of BaTiO
3 spectra to the applied electric field with time-resolved technique, and found that the pre-edge eg peak and the shoulder structure reflects different characteristics of dielectric properties.