Decelerated lattice excitation and absence of bulk phonon modes at surfaces : Ultra-fast electron diffraction from Bi(111) surface upon fs-laser excitation
| Autor: | Manuel Ligges, A. Kalus, Uwe Bovensiepen, C. Streubühr, D. von der Linde, B. Hafke, M. Horn-von Hoegen, T. Witte, A. Hanisch-Blicharski, V Tinnemann, Ping Zhou |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Diffraction
Materials science Phonon 02 engineering and technology 01 natural sciences Molecular physics law.invention ARTICLES law 0103 physical sciences lcsh:QD901-999 010306 general physics Instrumentation Spectroscopy Radiation Surface phonon Surfaces and Interfaces Physik (inkl. Astronomie) 021001 nanoscience & nanotechnology Condensed Matter Physics Laser Electron diffraction Femtosecond lcsh:Crystallography 0210 nano-technology Ultrashort pulse Excitation |
| Zdroj: | Structural Dynamics Structural Dynamics, Vol 6, Iss 6, Pp 065101-065101-5 (2019) |
| Popis: | Ultrafast reflection high-energy electron diffraction is employed to follow the lattice excitation of a Bi(111) surface upon irradiation with a femtosecond laser pulse. The thermal motion of the atoms is analyzed through the Debye–Waller effect. While the Bi bulk is heated on time scales of 2 to 4 ps, we observe that the excitation of vibrational motion of the surface atoms occurs much slower with a time constant of 12 ps. This transient nonequilibrium situation is attributed to the weak coupling between bulk and surface phonon modes which hampers the energy flow between the two subsystems. From the absence of a fast component in the transient diffraction intensity, it is in addition concluded that truncated bulk phonon modes are absent at the surface. CA UDE |
| Databáze: | OpenAIRE |
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