High resolution Ce 3d-4f resonant photoemission study of CeNiSn and CePdSn

We have measured Ce 3d resonant photoemission spectra of CeNiSn and CePdSn with high resolution of E/Delta E similar to 4000. Although the Ce valences are close to 3+ for both compounds, the Ce 3d resonant spectra show strong er f(1) final states near the Fermi level compared with Ce 4d resonant spec tra. Calculations based on the single impurity model give consistent spectr al functions to the experimental results. The valence band states except fo r the Ce 4f states in the bulk are essentially the same as those in the sur face and consistent with the result of a band-structure calculation. (C) 19 99 Elsevier Science Ltd. All rights reserved.