Chapter 6
Atomic Chains, Clusters,
and Nanocrystals
Abstract Like adatoms, monoatomic chain ends, and atomic clusters with even
less-coordinated atoms demonstrate extraordinary properties due to dominance of
stronger quantum entrapment and polarization. Consistency between quantum calculations and XPS/STS observations resolves the origin of the unusual performance
of such even undercoordinated atoms. A combination of the XPS and AES, called
APECS, refines the energy shifts of both the core band and the valence band with
derived information of the screening effect and charge transport during reaction.
Highlights
• Au, Ag and Cu adatoms exhibit polarization dominance but Co and Si nanocrystals
entrapment.
• ZPS resolves the global entrapment and subjective polarization of even undercoordinated atoms.
• APECS resolves Ag, Cu, and Ni particle-substrate interaction and two-band
cooperative shift.
• Curvature enhanced entrapment and polarization entitles nanocrystals with novel
properties.
6.1 Observations
When the atomic CN increases from zero to the fcc bulk standard 12, the CL shifts
from the E ν (0) to a maximum at z = 2 and then recovers in a K
−1 fashion to the bulk
value of E ν (12). The amount of the CLS depends not only on the specific E ν (0) value
but also on the shape-and-size of the crystal. Au, Ag, Ni, Cu, Pd, Si, C, and their
compounds do follow this size CLS trend [1–12]. Calculations revealed that bonds in
Ag, Cu, Ni, and Fe atomic chains contracted by 12.5–18.5% with 0.5–2.0 eV gain of
bond energy [13, 14]. The 2p level of Cu 18 and Ni 18 clusters undergo positive shifts
from their bulk values by 0.7–0.8 eV while the average strain of the clusters increases
© 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_6
101
Atomic Chains, Clusters,
and Nanocrystals
Abstract Like adatoms, monoatomic chain ends, and atomic clusters with even
less-coordinated atoms demonstrate extraordinary properties due to dominance of
stronger quantum entrapment and polarization. Consistency between quantum calculations and XPS/STS observations resolves the origin of the unusual performance
of such even undercoordinated atoms. A combination of the XPS and AES, called
APECS, refines the energy shifts of both the core band and the valence band with
derived information of the screening effect and charge transport during reaction.
Highlights
• Au, Ag and Cu adatoms exhibit polarization dominance but Co and Si nanocrystals
entrapment.
• ZPS resolves the global entrapment and subjective polarization of even undercoordinated atoms.
• APECS resolves Ag, Cu, and Ni particle-substrate interaction and two-band
cooperative shift.
• Curvature enhanced entrapment and polarization entitles nanocrystals with novel
properties.
6.1 Observations
When the atomic CN increases from zero to the fcc bulk standard 12, the CL shifts
from the E ν (0) to a maximum at z = 2 and then recovers in a K
−1 fashion to the bulk
value of E ν (12). The amount of the CLS depends not only on the specific E ν (0) value
but also on the shape-and-size of the crystal. Au, Ag, Ni, Cu, Pd, Si, C, and their
compounds do follow this size CLS trend [1–12]. Calculations revealed that bonds in
Ag, Cu, Ni, and Fe atomic chains contracted by 12.5–18.5% with 0.5–2.0 eV gain of
bond energy [13, 14]. The 2p level of Cu 18 and Ni 18 clusters undergo positive shifts
from their bulk values by 0.7–0.8 eV while the average strain of the clusters increases
© 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_6
101