13.4 Scope
259
pairing off-centered-pyramid into the Cu 3 O 2 pairing-tetrahedron on the Cu(001) surface, and the corresponding change of the valence DOS. The annealing at ~550 K
de-hybridizes the oxygen of the chemisorbed system and hence demotes oxidation.
It is appropriate to describe a process of oxidation in terms of tetrahedron bond
making rather with evolution of energy states in place of dislocation of an individual
atom in a certain direction at a time, which represents essentially the true situation
and correlates observations in terms of crystallography, microscopy, and electron
spectroscopy. Besides, the sp
3 -orbital hybridization with creation of nonbonding
lone pairs and metal dipoles as well as the bond contraction are essential events for
chemisorption. Therefore, combining with STM and PES, VLEED provides such a
unique means that it collects comprehensive, nondestructive, and quantitative information from outside the second atomic layer of a surface and covers the valence band
energies and above.
This part is arranged as follows. Chapter 1 introduces briefly the VLEED spectrometrics and a survey on the knowledge acquired insofar about O-Cu(001) surface
reaction. Chapter 2 describes the VLEED calculation code for multi-atom and multiple beam diffraction developed by Thurgate [35] from the LEED package of Van
Hove and Tong’s [4], and a bond-band-barrier (3B) model of Sun [19, 20] addressing
the oxide tetrahedron bonding, the valence DOS evolution, and the change of the SPB
in general, for the specific O-Cu(001) surface in particular [19]. Chapter 3 justifies
numerically the models, the decoding strategies and the reliability of VLEED technique. Chapter 4 demonstrates outcomes of decoding a series of dynamic VLEED
I–E spectra from the O-Cu(001) surface. Quantitative information is gained about
the change of bond geometry, Brillouin zones, valence DOS, SPB, work function
and inner potential due to the reaction [54]. Evolutions of the bond geometry and
the valence DOS, particularly the DOS features of nonbonding states demonstrate
consistently four-stage dynamics of Cu 3 O 2 forming on Cu(001) surface upon exposure increase. The last Chap. 5 presents a perspective of further extension of the
knowledge gained in this part.
References
1. M.A. VanHove, W.H. Weinberg, C.-M. Chan, Low-Energy Electron Diffraction: Experiment,
Theory and Surface Structure Determination, vol. 6 (Springer Science & Business Media,
2012)
2. R.O. Jones, P.J. Jennings, LEED fine structure: origins and applications. Surf. Sci. Rep. 9(4),
165–196 (1988)
3. J. Pendry, G.P. Alldredge, Low energy electron diffraction: the theory and its application to
determination of surface structure. Phys. Today 30, 57 (1977)
4. M.A. Van Hove, S.Y. Tong, Surface Crystallography by LEED: Theory, Computation and
Structural Results, vol. 2 (Springer Science & Business Media, 2012
5. M. Van Hove, G. Somorjai, Adsorption and adsorbate-induced restructuring: a LEED
perspective. Surf. Sci. 299, 487–501 (1994)
6. E. McRae, Electron diffraction at crystal surfaces: I. generalization of Darwin’s dynamical
theory. Surf. Sci. 11(3), 479–491 (1968)
259
pairing off-centered-pyramid into the Cu 3 O 2 pairing-tetrahedron on the Cu(001) surface, and the corresponding change of the valence DOS. The annealing at ~550 K
de-hybridizes the oxygen of the chemisorbed system and hence demotes oxidation.
It is appropriate to describe a process of oxidation in terms of tetrahedron bond
making rather with evolution of energy states in place of dislocation of an individual
atom in a certain direction at a time, which represents essentially the true situation
and correlates observations in terms of crystallography, microscopy, and electron
spectroscopy. Besides, the sp
3 -orbital hybridization with creation of nonbonding
lone pairs and metal dipoles as well as the bond contraction are essential events for
chemisorption. Therefore, combining with STM and PES, VLEED provides such a
unique means that it collects comprehensive, nondestructive, and quantitative information from outside the second atomic layer of a surface and covers the valence band
energies and above.
This part is arranged as follows. Chapter 1 introduces briefly the VLEED spectrometrics and a survey on the knowledge acquired insofar about O-Cu(001) surface
reaction. Chapter 2 describes the VLEED calculation code for multi-atom and multiple beam diffraction developed by Thurgate [35] from the LEED package of Van
Hove and Tong’s [4], and a bond-band-barrier (3B) model of Sun [19, 20] addressing
the oxide tetrahedron bonding, the valence DOS evolution, and the change of the SPB
in general, for the specific O-Cu(001) surface in particular [19]. Chapter 3 justifies
numerically the models, the decoding strategies and the reliability of VLEED technique. Chapter 4 demonstrates outcomes of decoding a series of dynamic VLEED
I–E spectra from the O-Cu(001) surface. Quantitative information is gained about
the change of bond geometry, Brillouin zones, valence DOS, SPB, work function
and inner potential due to the reaction [54]. Evolutions of the bond geometry and
the valence DOS, particularly the DOS features of nonbonding states demonstrate
consistently four-stage dynamics of Cu 3 O 2 forming on Cu(001) surface upon exposure increase. The last Chap. 5 presents a perspective of further extension of the
knowledge gained in this part.
References
1. M.A. VanHove, W.H. Weinberg, C.-M. Chan, Low-Energy Electron Diffraction: Experiment,
Theory and Surface Structure Determination, vol. 6 (Springer Science & Business Media,
2012)
2. R.O. Jones, P.J. Jennings, LEED fine structure: origins and applications. Surf. Sci. Rep. 9(4),
165–196 (1988)
3. J. Pendry, G.P. Alldredge, Low energy electron diffraction: the theory and its application to
determination of surface structure. Phys. Today 30, 57 (1977)
4. M.A. Van Hove, S.Y. Tong, Surface Crystallography by LEED: Theory, Computation and
Structural Results, vol. 2 (Springer Science & Business Media, 2012
5. M. Van Hove, G. Somorjai, Adsorption and adsorbate-induced restructuring: a LEED
perspective. Surf. Sci. 299, 487–501 (1994)
6. E. McRae, Electron diffraction at crystal surfaces: I. generalization of Darwin’s dynamical
theory. Surf. Sci. 11(3), 479–491 (1968)