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Valence Band Spectroscopy in the Ultrasoft X-Ray Region (50 to 100 A)

Published online by Cambridge University Press:  06 March 2019

Burton L. Henke  and
Kazuo Taniguchi
Burton L. Henke
Affiliation:
University of Hawaii Honolulu, Hawaii 96822
Kazuo Taniguchi
Affiliation:
University of Hawaii Honolulu, Hawaii 96822
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Abstract

Transitions from the valence electron levels into the first relatively sharp inner sub-shell levels result in characteristic x-ray emissions in the 100-200 eV region. These spectra sensitively reflect the chemical state of the atoms which are representative of the submicron thickness of the sample surface under low energy x-ray excitation and of the first few molecular layers of the sample under electron excitation.

An optimized measurement method for this 50-100 A spectral region is “based upon single crystal spectrometry using a lead stearate analyzer which has high dispersion and efficiency and an energy width of about one eV in this wavelength range. Spectra are recorded using “tuned” proportional counter detection. In the work reported here, low energy x-ray excitation is used in order to minimize the possibility of radiation damage of the sample.

Each spectrum is calibrated for both energy and instrument transmission using known, sharp M lines of elements such as molybdenum, zirconium and yttrium which will bracket the spectraj. range under measurement. A simple method has been developed for "stripping" from the measured spectra the Lorentzian crystal width and the Gaussian collimation width in order to allow an estimation to be made of the actual emission line widths as well as the relative intensities.

In this report, as an illustrative application example, S-LII, III spectra are presented for a series of sulfur compounds in "both solid, and gas states. Manne's approximate molecular orbital interpretation of the x-ray emission spectra has been adopted and extended to apply to the LII, III spectra for second row elements.

Type
Soft X-Ray and Surface Analysis
Information
Advances in X-Ray Analysis , Volume 19: Twenty-Fourth Annual Conference on Applications of X-ray Analysis, August 6-8, 1975 , 1975 , pp. 627 - 641
Copyright
Copyright © International Centre for Diffraction Data 1975

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References

1. Henke, B. L. and Tester, M. A., Advances in X-Ray Analysis (Plenum Press, New York, 1975), Vol. 18, p. 76.Google Scholar
2. Henke, B. L. and Taniguchi, K., (to be published in the Journal of Applied Physics).Google Scholar
3. Henke, B. L., Advances in X-Ray Analysis (Plenum Press, New York, 1966), Vol. 9, p. 430.Google Scholar
4. Kortela, E. K. and Karras, M., Spectrochim. Acta A 29, 1293 (1972).Google Scholar
5. Krause, M. O., Chem. Phys. Lett. 10, 65 (l97l).Google Scholar
6. Henke, B. L. and Ebisu, E. S., Advances in X-Ray Analysis (Plenum Press, New York, 1973), Vol. 17, p. 150.Google Scholar
7. Manne, R., J. Chem. Phys. 52, 5733 (1970).Google Scholar
8. Karlsson, G. and Manne, R., Physica Scripta 4, 119 (l97l).Google Scholar
9. Taniguchi, K. and Henke, B. L. (to be published in the Journal of Chemical Physics).Google Scholar
10. Pople, J. A. and Beveridge, D. L., Approximate Molecular Orbital Theory (McGraw-Hill, New York, 1970).Google Scholar
11. Whitehead, H. C., Ph.D. Thesis, University of Hawaii, 1973.Google Scholar
12. Manne, R., J. Chem. Phys. 52, No. 11, 5733 (1970).Google Scholar
13. Kortela, E., Suoninen, E., Karras, M. and Manne, R., J. Phys. B: Atom. Molec. Phys. 5, 2032 (1972).Google Scholar
14. Laporte, Z. Phys. 23, 135 (1924).Google Scholar
15. Koopmans, T., Physica 1, 104 (1934).Google Scholar
16. Johansen, H., Theoret. Chim. Acta (Berl.) 32, 273 (1974).Google Scholar
17. Parratt, L. G., Phys. Rev. 50, 1 (1936).Google Scholar
18. In order to estimate the LII and LIII energies for Na2SO4, we have used the values relative to elemental sulfur given by Siegtahn, K., Nordling, C., Fahlman, A., Nordberg, R., Hamrin, K., Hedman, J., Johansson, G., Bergmark, T., Karlsson, S. E., Lindgren, I., and Lindherg, B., ESCA (North Holland Press, 1967) and those for elemental sulfur given by Bearden, J. A. and Burr, A. F., “Atomic Energy Levels,” NYO 2543-1 (Federal Scientific and Technical Information, U.S. Dept, of Commerce, Springfield, Virginia 22151).Google Scholar
19. Prins, R. and Novakov, T., Chem. Phys. Lett. 9, 593 (1971).Google Scholar
20. Manne, R., J. Chem. Phys. 46, 4645 (1967).Google Scholar