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Ab initio investigation of the surface properties of dispenser B-type and scandate thermionic emission cathodes

Appl. Phys. Lett. 94, 184102 (2009); doi:10.1063/1.3129193

Published 4 May 2009

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Vasilios Vlahos,1 Yueh-Lin Lee,1 John H. Booske,2 Dane Morgan,3 Ladislav Turek,4 Mark Kirshner,4 Richard Kowalczyk,4 and Craig Wilsen4
1Interdisciplinary Materials Science Program, University of Wisconsin, Madison, Wisconsin 53706, USA
2Department of Electrical and Computer Engineering and Interdisciplinary Materials Science Program, University of Wisconsin, Madison, Wisconsin 53706, USA
3Department of Materials Science and Engineering and Interdisciplinary Materials Science Program, University of Wisconsin, Madison, Wisconsin 53706, USA
4L-3 Communications—Electron Devices, 960 Industrial Rd., San Carlos, California 94070, USA
Scandate cathodes (BaxScyOz on W) are important thermionic electron emission materials whose emission mechanism remains unclear. Ab initio modeling is used to investigate the surface properties of both scandate and traditional B-type (Ba–O on W) cathodes. We demonstrate that the Ba–O dipole surface structure believed to be present in active B-type cathodes is not thermodynamically stable, suggesting that a nonequilibrium steady state dominates the active cathode's surface structure. We identify a stable, low work function BaxScyOz surface structure, which may be responsible for some scandate cathode properties and demonstrate that multicomponent surface coatings can lower cathode work functions. ©2009 American Institute of Physics
History: Received 19 February 2009; accepted 13 April 2009; published 4 May 2009
Permalink: http://link.aip.org/link/?APPLAB/94/184102/1
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KEYWORDS and PACS

Keywords
PACS
  • 79.40.+z
    Thermionic emission (from surfaces)
  • 73.30.+y
    Surface double layers, Schottky barriers, and work functions
  • 73.20.At
    Surface states, band structure, electron density of states
  • 71.15.Mb
    Density functional theory, local density approximation, gradient and other corrections (condensed matter electronic structure)
  • 68.35.bt
    Surface structure of other materials
  • YEAR: 2009

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PUBLICATION DATA

ISSN:
0003-6951 (print)   1077-3118 (online)
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REFERENCES (25)
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  1. Y. Wang, J. Wang, W. Liu, K. Zhang, and J. Li, IEEE Trans. Electron Devices 54, 1061 (2007).
  2. S. Taguchi, T. Aida, and S. Yamamoto, IEEE Trans. Electron Devices 31, 900 (1984).
  3. S. Yamamoto, T. Yaguchi, S. Sasaki, and I. Watanabe, Jpn. J. Appl. Phys., Part 2 28, L865 (1989).
  4. J. Hasker and C. Crombeen, IEEE Trans. Electron Devices 37, 2589 (1990).
  5. P. M. Zagwijn, J. W. M. Frenken, U. van Slooten, and P. A. Duine, Appl. Surf. Sci. 111, 35 (1997).
  6. W. Müller, Appl. Surf. Sci. 111, 30 (1997).
  7. G. Lesny and R. Forman, IEEE Trans. Electron Devices 37, 2595 (1990).
  8. R. S. Raju and C. E. Maloney, IEEE Trans. Electron Devices 41, 2460 (1994).
  9. W. Liu, K. Zhang, Y. Wang, K. Pan, X. Gu, J. Wang, J. Li, and M. Zhou, Appl. Surf. Sci. 251, 80 (2005).
  10. H. Yuan, X. Gu, K. Pan, Y. Wang, W. Liu, K. Zhang, J. Wang, M. Zhou, and J. Li, Appl. Surf. Sci. 251, 106 (2005).
  11. G. Miram, L. Ives, M. Read, R. Wilcox, M. Cattelino, and B. Stockwell, Fifth IEEE International Vacuum Electronics Conference Proceedings, 2004 (unpublished), p. 303.
  12. R. Forman, Appl. Surf. Sci. 2, 258 (1979).
  13. G. A. Haas, A. Shih, and C. R. K. Marrian, Appl. Surf. Sci. 16, 139 (1983).
  14. A. Van Oostrom and L. Augustus, Appl. Surf. Sci. 2, 173 (1979).
  15. S. Yamamoto, S. Sasaki, S. Taguchi, I. Watanabe, and N. Koganezawa, Appl. Surf. Sci. 33, 1200 (1988).
  16. G. Gärtner, P. Geittner, H. Lydtin, and A. Ritz, Appl. Surf. Sci. 111, 11 (1997).
  17. P. Hohenberg and W. Kohn, Phys. Rev. 136, B864 (1964).
  18. D. M. Ceperley and B. J. Alder, Phys. Rev. Lett. 45, 566 (1980).
  19. J. P. Perdew, K. Burke, and Y. Wang, Phys. Rev. B 54, 16533 (1996).
  20. G. Kresse and D. Joubert, Phys. Rev. B 59, 1758 (1999).
  21. G. Kresse and J. Furthmüller, Comput. Mater. Sci. 6, 15 (1996).
  22. H. J. Monkhorst and J. D. Pack, Phys. Rev. B 13, 5188 (1976).
  23. E. Heifets, J. Ho, and B. Merinov, Phys. Rev. B 75, 155431 (2007).
  24. P. Zalm, in Electronics and Electron Physics, edited by L. Marton (Academic, New York, 1968), Vol. 25.
  25. R. Forman, J. Appl. Phys. 47, 5272 (1976).

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