Chapter 13
Introduction
Abstract Extending the very low-energy electron diffraction (VLEED) crystallography to the bond-band-barrier forming dynamics has been proven to offer comprehensive information on bond geometry from the outermost two atomic layers and
on electron performance from the valence band and above, and on surface potential barrier evolution upon chemisorption, which are consistent with STM and PES
observations.
Highlights
• The impact of extending LEED crystallography to bond-band-barrier forming
dynamics is enormous.
• VLEED monitors the behavior of atoms, valence electrons, and chemisorption
bonding dynamics.
• VLEED probes bond geometry, energy states, potential function in the outermost
two atomic layers.
• VLEED resolves work function, muffin-tin inner potential, and Brillouin zone
boundaries.
13.1 LEED, VLEED, STM/S, and PES
LEED crystallography is an important technique for studying the geometric arrangement of atoms in the sublayers of crystalline surfaces [1, 2]. In normal LEED, the
scattering of electron beams with energies greater than 30 eV is dominated by interaction between the incident electron beams and the ion cores of a number of stacking
layers of atoms [3, 4]. The LEED pattern portrays the two-dimensional structure of
the surface lattice. By studying how the diffraction intensities change with increasing
the energy of the incident electron beam at different azimuth angles, it is possible
to infer details about the vertical location of the atoms and to measure the distance
of the surface interlayer spacing, as does the X-ray diffraction for bulk crystals. The
analysis of LEED patterns and LEED I-E profiles is very important, and LEED is
so established as a prestigious tool in surface science for analyzing the structure of
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Singapore Pte Ltd. 2020
C. Q. Sun, Electron and Phonon Spectrometrics,
https://doi.org/10.1007/978-981-15-3176-7_13
251
Introduction
Abstract Extending the very low-energy electron diffraction (VLEED) crystallography to the bond-band-barrier forming dynamics has been proven to offer comprehensive information on bond geometry from the outermost two atomic layers and
on electron performance from the valence band and above, and on surface potential barrier evolution upon chemisorption, which are consistent with STM and PES
observations.
Highlights
• The impact of extending LEED crystallography to bond-band-barrier forming
dynamics is enormous.
• VLEED monitors the behavior of atoms, valence electrons, and chemisorption
bonding dynamics.
• VLEED probes bond geometry, energy states, potential function in the outermost
two atomic layers.
• VLEED resolves work function, muffin-tin inner potential, and Brillouin zone
boundaries.
13.1 LEED, VLEED, STM/S, and PES
LEED crystallography is an important technique for studying the geometric arrangement of atoms in the sublayers of crystalline surfaces [1, 2]. In normal LEED, the
scattering of electron beams with energies greater than 30 eV is dominated by interaction between the incident electron beams and the ion cores of a number of stacking
layers of atoms [3, 4]. The LEED pattern portrays the two-dimensional structure of
the surface lattice. By studying how the diffraction intensities change with increasing
the energy of the incident electron beam at different azimuth angles, it is possible
to infer details about the vertical location of the atoms and to measure the distance
of the surface interlayer spacing, as does the X-ray diffraction for bulk crystals. The
analysis of LEED patterns and LEED I-E profiles is very important, and LEED is
so established as a prestigious tool in surface science for analyzing the structure of
© The Editor(s) (if applicable) and The Author(s), under exclusive license
to Springer Nature Singapore Pte Ltd. 2020
C. Q. Sun, Electron and Phonon Spectrometrics,
https://doi.org/10.1007/978-981-15-3176-7_13
251