Abstract
We have studied the chemisorption of atomic hydrogen on the basal plane of natural graphite single crystals. LEED and angle-resolved photoemission were used to characterize the clean surface. The adsorption of H saturates at rather low exposures, accompanied by a decrease of the work function by Δφ=(100±20) meV. The photoemission spectra indicate a clear carbon-hydrogen interaction, leading to shifts of substrate bands by up to about 200 meV. No detectable etching of the surface occurs at room temperature, in agreement with earlier work. Our results are qualitatively consistent with theoretical considerations about a strong H(1s)-C(2p z) chemical bond.
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References
E. Vietzke, J. Philipps: Fusion Technology 15, 108 (1989)
V. Philipps, E. Vietzke, M. Erdweg: J. Nucl. Mater. 162–164, 550 (1989); see also same journal p. 520
Y. Matsuzaki, JFT-2M-Team: J. Nucl. Mater. 162–164, 752 (1989)
J. Bohdansky, J. Roth: Effects 89, 49 (1985)
E. Vietzke, M. Erdweg, K. Flaskamp, V. Philipps: Proc. 9th Int'l Vacuum Congress and 5th Int'l Conf. Solid Surfaces, Madrid (1983) p. 627
A.A. Haas, J.W. Davis, O. Auciello, P.C. Stangeby, E. Vietzke, K. Flaskamp, V. Philipps: J. Nucl. Mater. 145–147, 412 (1987); see also same journal p. 292
K. Christmann: Surf. Sci. Reps. 9, 1 (1988)
A.R. Law, M.T. Johnson, H.P. Hughes: Phys. Rev. B 34, 4289 (1986)
D. Marchand, C. Frétigny, M. Lagues, F. Batallan, Ch. Simon, I. Roseman, R. Pinchaux: Phys. Rev. B 30, 4788 (1984)
I. Schäfer, M. Schlüter, M. Skibowski: Phys. Rev. B 35, 7663 (1987)
B. Reihl, J.K. Gimzewski, J.M. Nicholls, E. Tosatti: Phys. Rev. B 33, 5770 (1986)
T. Takahashi, M. Tokailin, T. Sagawa: Phys. Rev. B 32, 8317 (1985)
K. Jost: J. Phys. E 12 1006 (1979)
We thank Prof. G. Schönhense for supplying us with constructional details
R.C. Tatar, S. Rabii: Phys. Rev. B 25, 4126 (1982) and several references therein
E.W. Plummer, W. Eberhardt: Adv. Chem. Phys. 49, 533 (1982)
F.J. Himpsel: Adv. Phys. 32, 1 (1983)
P. Oelhafen, J.L. Freeouf: J. Vas. Sci. Technol. A 1, 96 (1983)
R.C. Claessens, H. Carstensen, M. Skibowski: Phys. Rev. B 38, 12582 (1988)
A.R. Law, J.J. Barry, H.P. Hughes: Phys. Rev. B 29, 5332 (1983)
M. Fink, M.R. Martin: Surf. Sci. 29, 303 (1972)
E. Vietzke, K. Flaskamp, V. Philipps: J. Nucl. Mater. 111–112, 763 (1982)
U. Kürpick, G. Meister, A. Goldmann: To be published in Appl. Phys. (1992)
A.J. Bennett, B. McCarroll, R.P. Messmer: Surf. Sci. 24, 191 (1971)
R. Dovesi, C. Pisani, F. Ricca, C. Roetti: J. Chem. Phys. 65, 4116 (1976); J. Chem. Phys. 65, 3075 (1976)
R. Dovesi, C. Pisani, C. Roetti: Chem. Phys. Letters 81, 498 (1981); Surf. Sci. 72, 140 (1978)
J.P. Chen, R.T. Yang: Surf. Sci. 210, 481 (1981)