X-RAY PHOTOELECTRON DIFFRACTION FOR PURE AND NB-DOPED KTAO3 - SITE DETERMINATION FOR THE NB ATOMS

We present a set of polar-angle-dependent x-ray photoelectron spectra (XPS) obtained from in situ cleaved single-crystalline pure KTaO3. The variation of the intensity for different angles can be explained by t he diffraction of the emitted electrons by the surrounding atoms of th e emitter and thus may be used as a 'fingerprint' for the location of emitting impurity atoms. Measurements were carried out on niobium-dope d KTaO3. The atomic position of the niobium atoms was deduced from the comparison of the angle-dependent spectra, giving a clear hint that t antalum is replaced by niobium.