The interaction of highly vibrationally excited molecules with surfaces: vibrational relaxation and reaction of NO(v) at Cu(111) and O/Cu(111)

Abstract

We have studied the reaction and inelastic scattering of ground and vibrationally excited NO on Cu(111). We employed laser-based techniques to prepare NO in vibrationally excited states, stimulated emission pumping (SEP) to prepare v=13 and v=15 and infrared overtone pumping to prepare v=2. Laser ionization detection schemes were developed for probing the state distribution of highly vibrationally excited NO molecules. Ground-state NO(v=0) dissociates at Cu(111) with a probability of ≈2×10^-4, with little dependence on the translational energy in the range between 29 and 65 kJ mol^-1. The dissociation probability is strongly enhanced by vibrational excitation to v=13 and 15. The dissociation continues until the oxygen coverage on Cu(111) reaches saturation. For highly excited NO(v=13, 15) scattering from O/Cu(111), we have seen efficient multi-quantum relaxation (up to Δv=-5). For NO(v=2), in contrast, the survival probability is nearly 90%. Measurements of the translational and rotational state distributions after scattering support a direct-inelastic mechanism for vibrational relaxation, with strong flow of energy into the surface. The branching ratios for vibrational relaxation are independent of the kinetic energy in our experiments.

References

1. W. C. Polanyi and W. H. Wong, J. Chem. Phys., 1969, 51, 1439.
2. J. C. Polanyi, Acc. Chem. Res., 1972, 5, 161.
3. C. E. Hamilton, J. L. Kinsey and R. W. Field, Annu. Rev. Phys. Chem., 1986, 37, 493.
4. X. Yang and A. M. Wodtke, J. Chem. Phys., 1990, 92, 116.
5. F. F. Crim, Annu. Rev. Phys. Chem., 1993, 44, 397.
6. F. F. Crim, J. Phys. Chem., 1996, 100, 12725.
7. M. Asscher, W. L. Guthrie, T.-H. Lin and G. A. Somorjai, Phys. Rev. Lett., 1982, 49, 76.
8. D. A. Mantell, Y.-F. Maa, S. B. Ryali, G. L. Haller and J. B. Fenn, J. Chem. Phys., 1983, 78, 6338.
9. C. T. Rettner, F. Fabre, J. Kimman and D. J. Auerbach, Phys. Rev. Lett., 1985, 55, 1904.
10. B. D. Kay, T. D. Raymond and M. E. Coltrin, Phys. Rev. Lett., 1987, 59, 2792.
11. C. T. Rettner, D. J. Auerbach and H. A. Michelsen, Phys. Rev. Lett., 1992, 68, 2547.
12. A. Hodgson, P. Samson, A. Wight and C. Cottrel, Phys. Rev. Lett., 1997, 78, 963.
13. B. N. J. Persson and P. Avouris, Surf. Sci., 1997, 390, 45.
14. B. N. J. Persson and J. W. Gadzuk, Surf. Sci., 1998, 410, L779.
15. A. Sinha, J. D. Thoemke and F. Crim, J. Chem. Phys., 1992, 96, 372.
16. C. A. Rogaski, J. M. Price, J. A. Mack and A. M. Wodtke, Geophys. Res. Lett., 1993, 20, 2885.
17. R. L. Miller, A. G. Suits, P. L. Houston, R. Toumi, J. A. Mack and A. M. Wodtke, Science, 1994, 265, 1831.
18. D. W. Arnold, M. Korolik, C. Wittig and H. Reisler, Chem. Phys. Lett., 1998, 282, 313.
19. C. A. Michaels, A. S. Mullin, P. Jeunghee, J. Z. Chou and G. W. Flynn, J. Chem. Phys., 1988, 108, 2744.
20. C. T. Rettner, H. E. Pfnür, H. Stein and D. J. Auerbach, J. Vac. Sci. Technol., A, 1988, 6, 899.
21. M. Gostein and G. O. Sitz, J. Chem. Phys., 1997, 106, 7378.
22. H. Hou, Y. Huang, C. T. Rettner, S. J. Gulding, D. J. Auerbach and A. M. Wodtke, J. Chem. Phys., 1999, 110, 10660.
23. H. Hou, Y. Huang, C. T. Rettner, S. J. Gulding, D. J. Auerbach and A. M. Wodtke, Science, 1999, 284, 1647.
24. Y. Huang and M. Sulkes, Rev. Sci. Instrum., 1994, 65, 3969.
25. The probe light was generated by doubling the output of a Λ-Physik FL3002 dye laser. The pump source of the dye laser was the third harmonic light (λ = 355 nm) of a Nd: YAG Laser (Continuum PowerLite 7010).
26. The nomenclature for transition branches follow that described by Hertzberg.
27. G. Herzberg, Spectra of Diatomic Molecules, Robert E. Krieger Publishing Co., Inc., 1989, vol. 1, pp. 259, 269.
28. The fundamental light from a Nd: YAG (Continuum PowerLite 8010s) was mixed with the output of a dye laser (Continuum ND 6000, I = 770 nm) in a Continuum IR-package with a LiNbO₃ crystal. The dye laser was pumped by the second harmonic (λ = 532 nm) of the same Nd: YAG laser.
29. M. H. Matloob and M. W. Roberts, Phys. Scr., 1977, 16, 420; W. A. Brown, P. Gardner and D. A. King, J. Phys. Chem., 1995, 99, 7065.
30. F. H. P. M. Habraken, E. P. Kieffer and G. A. Bootsma, Surf. Sci., 1979, 83, 45.
31. J. A. Rodriguez and J. Hrbek, J. Vac. Sci. Technol., A, 1994, 12, 2140.
32. A. W. Kleyn, A. C. Luntz and D. J. Auerbach, Phys. Rev. Lett., 1981, 47, 1169.
33. A. C. Luntz, A. W. Kleyn and D. J. Auerbach, Phys. Rev. B: Condens. Matter, 1982, 25, 4273.
34. A. C. Luntz, A. W. Kleyn and D. J. Auerbach, Vacuum, 1983, 33, 781.
35. A. C. Luntz, A. W. Kleyn and D. J. Auerbach, J. Chem. Phys., 1982, 76, 737.
36. C. Amiot, J. Mol. Spectrosc., 1982, 94, 150.
37. R. Engleman Jr., P. E. Rouse, H. M. Peek and e. V. D. Baiamont, Beta and Gamma band systems of nitri coxide, Los Alamos Scientific Laboratory of the University of California, 1970, LA-4364, UC-34, Physics, TID-4500.
38. R. N. Zare, Angular Momentum: Understanding spatial aspects in chemistry and physics, Wiley-Interscience, New York, 1988.
39. P. M. Morse, Phys. Rev., 1929, 34, 57.
40. J. C. Tully and M. J. Cardillo, Science, 1984, 223, 445.
41. B. E. Hayden and C. L. A. Lamont, Phys. Rev. Lett., 1989, 63, 1823.
42. G. Anger, A. Winkler and K. D. Rendulic, Surf. Sci., 1989, 220, 1.
43. J. Harris, Surf. Sci., 1989, 221, 335.
44. J. K. Nørskov, J. Chem. Phys., 1989, 90, 7461.
45. S. Küchenhoff, W. Brenig and Y. Chiba, Surf. Sci., 1991, 245, 389.
46. S. Holloway and G. Darling, Comments At. Mol. Phys., 1992, 27, 335.
47. C. T. Rettner, D. J. Auerbach and H. A. Michelsen, Phys. Rev. Lett., 1992, 68, 1164.
48. C. T. Rettner, F. Fabre, J. Kimman and D. J. Auerbach, Phys. Rev. Lett., 1985, 55, 1904.
49. S. Holloway and J. W. Gadzuk, J. Chem. Phys., 1985, 82, 5203.
50. D. Newns, Surf. Sci., 1985, 171, 600.
51. W. Gadzuk and S. Holloway, Chem. Phys. Lett., 1985, 114, 314.
52. J. W. Gadzuk and S. Holloway, Phys. Rev. B: Condens. Matter, 1986, 33, 4298.
53. C. T. Rettner, J. Kimman, F. Fabre, D. J. Auerbach and H. Morawitz, Surf. Sci., 1987, 192, 107.