Abstract
A theoretical study of collective electronic excitations in Pd at low-energy (from 0 to ∼3eV) domain is reported. The calculations were performed with full inclusion of the electron band structure obtained within self-consistent pseudopotential approach. We show that the presence in Pd of two kinds of carriers (in s p and d bands) at the Fermi level produces dramatic modification of the excitation spectra in this energy range in comparison with free-electron-like model prediction. In particular, at small momenta a peculiar plasmon mode with characteristic sound-like dispersion-an acoustic plasmon-is predicted to exist in this material. This mode has strong directional dependence on the momentum transfer: whereas for momenta along the 100 and 111 symmetry directions it arises as a single mode up to ∼1eV, along the 110 direction two acoustic modes (one of which disperses up to ∼2.5eV) with different slope exist. As in many metallic systems, e.g., in transition metals, there are energy bands with large difference in the Fermi velocities, we expect that the existence of such plasmon mode must be a rather general phenomenon. Additionally, present calculations reveal other well-defined features in the energy-loss spectra in this low-energy range due to numerous interband transitions.
Original language | English |
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Article number | 245114 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 80 |
Issue number | 24 |
DOIs | |
Publication status | Published - 21 Dec 2009 |
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ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials
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Low-energy collective electronic excitations in Pd metal. / Silkin, Vyacheslav Mikhaylovich; Chernov, I. P.; Koroteev, Yury Mikhaylovich; Chulkov, E. V.
In: Physical Review B - Condensed Matter and Materials Physics, Vol. 80, No. 24, 245114, 21.12.2009.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Low-energy collective electronic excitations in Pd metal
AU - Silkin, Vyacheslav Mikhaylovich
AU - Chernov, I. P.
AU - Koroteev, Yury Mikhaylovich
AU - Chulkov, E. V.
PY - 2009/12/21
Y1 - 2009/12/21
N2 - A theoretical study of collective electronic excitations in Pd at low-energy (from 0 to ∼3eV) domain is reported. The calculations were performed with full inclusion of the electron band structure obtained within self-consistent pseudopotential approach. We show that the presence in Pd of two kinds of carriers (in s p and d bands) at the Fermi level produces dramatic modification of the excitation spectra in this energy range in comparison with free-electron-like model prediction. In particular, at small momenta a peculiar plasmon mode with characteristic sound-like dispersion-an acoustic plasmon-is predicted to exist in this material. This mode has strong directional dependence on the momentum transfer: whereas for momenta along the 100 and 111 symmetry directions it arises as a single mode up to ∼1eV, along the 110 direction two acoustic modes (one of which disperses up to ∼2.5eV) with different slope exist. As in many metallic systems, e.g., in transition metals, there are energy bands with large difference in the Fermi velocities, we expect that the existence of such plasmon mode must be a rather general phenomenon. Additionally, present calculations reveal other well-defined features in the energy-loss spectra in this low-energy range due to numerous interband transitions.
AB - A theoretical study of collective electronic excitations in Pd at low-energy (from 0 to ∼3eV) domain is reported. The calculations were performed with full inclusion of the electron band structure obtained within self-consistent pseudopotential approach. We show that the presence in Pd of two kinds of carriers (in s p and d bands) at the Fermi level produces dramatic modification of the excitation spectra in this energy range in comparison with free-electron-like model prediction. In particular, at small momenta a peculiar plasmon mode with characteristic sound-like dispersion-an acoustic plasmon-is predicted to exist in this material. This mode has strong directional dependence on the momentum transfer: whereas for momenta along the 100 and 111 symmetry directions it arises as a single mode up to ∼1eV, along the 110 direction two acoustic modes (one of which disperses up to ∼2.5eV) with different slope exist. As in many metallic systems, e.g., in transition metals, there are energy bands with large difference in the Fermi velocities, we expect that the existence of such plasmon mode must be a rather general phenomenon. Additionally, present calculations reveal other well-defined features in the energy-loss spectra in this low-energy range due to numerous interband transitions.
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U2 - 10.1103/PhysRevB.80.245114
DO - 10.1103/PhysRevB.80.245114
M3 - Article
AN - SCOPUS:77954717738
VL - 80
JO - Physical Review B
JF - Physical Review B
SN - 0163-1829
IS - 24
M1 - 245114
ER -