Valence Hole Localization in Molecular Auger Decay


Studies of the unimolecular decay, following the excitation of core electrons of the carbon and fluorine atoms in carbon tetrafluoride and silicon and fluorine in silicon tetrafluoride by monochromatic, synchrotron radiation, provided evidence for a “valence bond depopulation” fragmentation mechanism. The fragmentation processes were examined using time-of flight mass spectroscopy. The mass spectra show the distribution of ions collected in coincidence with low and high energy electrons. Distinct changes in the mass spectra with atomic site of excitation and photon energy are observed. The observation of F2+ ions in the time-of-flight mass spectra following excitation of a fluorine is electron in SiF4 is significant because it provides direct evidence for the formation of a localized, two-hole, final valence state that persists on the time scale of fragmentation. In contrast, the lack of F2+ ions from CF4, indicates that the fragmentation occurs through a delocalized two-hole state.

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  1. 1.

    (a) E. Antonides, E.C. Janse, and G.A. Sawatsky, Phys. Rev. 815, 1669 (1977); (b) G.A. Sawatzky, Phys. Rev. Lett. 39, 504 (1977); (c) G.A. Sawatzky and A. Lenselink, Phys. Rev. B 21, 1790 (1980).

    Article  Google Scholar 

  2. 2.

    M. Cini, Surf. Sci. 87, 483 (1979); Solid State Commun. 20, 605 (1976); 24, 681 (1977); Phys. Rev. B 17, 2788 (1978).

    CAS  Article  Google Scholar 

  3. 3.

    (a) P.J. Bassett, T.E. Gallon, M. Prutton, and J.A.D. Matthew, Surf. Sci. 33, 213 (1972); (b) D.R. Jennison, J. Vac. Sci. Technol. 20, 548 (1982).

    Article  Google Scholar 

  4. 4.

    (a) T.D. Thomas and P. Weightman, Chem Phys. Lett. 81, 325 (1981); (b) P. Weightman, T.D. Thomas, and D.R. Jennison, J. Chem. Phys. 78, 1652 (1983).

    Article  Google Scholar 

  5. 5.

    R.R Rye, D.R. Jennison, and J.E. Houston, J. Chem. Phys. 73, 4867 (1980).

    CAS  Article  Google Scholar 

  6. 6.

    R.R. Rye, and J.E. Houston, J. Chem. Phys. 78, 4321 (1983).

    CAS  Article  Google Scholar 

  7. 7.

    (a) D.R. Jennison, J.A. Kelber, and R.R. Rye, Phys. Rev. B 25, 1384 (1982); (b) P.J. Feibelman, Surf. Sci. 102, L51 (1981); (c) D.E. Ramaker, C.T. White, and J.S. Muday, J. Vac. Sci. Technol. 18, 748 (1981).

    Article  Google Scholar 

  8. 8.

    J. Murakami, M.C. Nelson, S.L. Anderson, D.M. Hanson, J. Chem. Phys., 85. 5755 (1986)

  9. 9.

    D.A. Lapiano-Smith, C.I. Ma, K.T. Wu and D.M. Hanson, J. Chem. Phys., in press.

  10. 10.

    N. Saito and I.H. Suzuki, Chem. Phys. Lett. 129, 419 (1986).

    CAS  Article  Google Scholar 

  11. 11.

    R.R. Rye and J.E. Houston, Acc. Chem. Res. 17, 41 (1984).

    CAS  Article  Google Scholar 

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Correspondence to D. A. Lapiano-Smith.

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Lapiano-Smith, D.A., Ma, C.I., Wu, K.T. et al. Valence Hole Localization in Molecular Auger Decay. MRS Online Proceedings Library 131, 523 (1988).

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