PHOTOEMISSION STUDY OF SURFACE LAYERS ON PUFE-2
The core levels and the valence band of polycrystalline PuFe-2 were observed by XPS (Mg-K-alpha, 1253.6 eV) and UPS (He I, 21.2 eV and He II, 40.8 eV), by use of a Leybold photoemission spectrometer, modified in order to work on radioactive materials. The base pressure in the analysis chamber was 7 nPa, and raised up to 300 nPa during UPS measurements. The samples were prepared by mixing stoichiometric amounts of the metals and melting by induction heating Iin vacuo. They were then ground with SiC, transferred into the spectrometer and cleaned by repeated Ar**+ sputtering and heating cycles (250 degrees C). XPS study of the Pu 4f and Fe 2p core levels revealed in the beginning an oxide layer consisting of PuO-2 and Fe-2O-3. However, during the cleaning procedure, the surface layer composition changed to Pu-2O-3 and metallic Fe. This result will be discussed in comparison with the results of investigations of other AB-2 compounds, where A is a lanthanide and B a transition metal. Valence spectra by XPS and UPS, taking advantage of the variation of the photoemission cross section are being measured in order to identify the contribution of 5f electrons.
Bibliographic Reference: 14EMES JOURNEES DES ACTINIDES, DAVOS (SWITZERLAND), APRIL 2-3, 1984 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING PAPER E 31432 ORA
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Record Number: 1989122089200 / Last updated on: 1987-01-01
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