X-RAY PHOTOELECTRON-SPECTROSCOPY AND AUGER-ELECTRON SPECTROSCOPY STUDIES OF FERROELECTRIC (PB,LA)TIO3 THIN-FILMS PREPARED BY A MULTI-ION-BEAM REACTIVE COSPUTTERING TECHNIQUE

X-ray photoelectron spectroscopy and Auger electron spectroscopy studi es were performed for determining the chemical composition, compositio nal depth profile, and the chemical bondings of ferroelectric (Pb,La) TiO3 thin films deposited by a multi-ion-beam reactive cosputtering te chnique. It was found that the chemical composition of the films and t he chemical bondings of lead in the near surface region are different from those in the ''bulk'' region of the films. The films are Pb enric hed and the lead atoms exist mainly in the forms of PbO(ads) (i.e., ox ygen-chemisorbed lead) and PbTiO3 in the near surface region, whereas in the bulk region, the chemical composition is in good agreement with stoichiometry and lead atoms exist in the form of PbTiO3. It is belie ved that the effect of Pb enrichment in the near surface regions is an intrinsic phenomenon of lead-contained thin films, which may be attri butable to the oxygen-chemisorbed lead.