Ultrafast electron diffraction from a Bi(111) surface: Impulsive lattice excitation and Debye–Waller analysis at large momentum transfer
The lattice response of a Bi(111) surface upon impulsive femtosecond laser excitation is studied with time-resolved reflection high-energy electron diffraction. We employ a Debye–Waller analysis at large momentum transfer of 9.3 Å−1 ≤ Δ k ≤ 21.8 Å−1 in order to study the lattice excitation dynamics...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
AIP Publishing LLC and ACA
2019-05-01
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| Series: | Structural Dynamics |
| Online Access: | http://dx.doi.org/10.1063/1.5093637 |
| _version_ | 1819058166024896512 |
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| author | V. Tinnemann C. Streubühr B. Hafke A. Kalus A. Hanisch-Blicharski M. Ligges P. Zhou D. von der Linde U. Bovensiepen M. Horn-von Hoegen |
| author_facet | V. Tinnemann C. Streubühr B. Hafke A. Kalus A. Hanisch-Blicharski M. Ligges P. Zhou D. von der Linde U. Bovensiepen M. Horn-von Hoegen |
| author_sort | V. Tinnemann |
| collection | DOAJ |
| description | The lattice response of a Bi(111) surface upon impulsive femtosecond laser excitation is studied with time-resolved reflection high-energy electron diffraction. We employ a Debye–Waller analysis at large momentum transfer of 9.3 Å−1 ≤ Δ k ≤ 21.8 Å−1 in order to study the lattice excitation dynamics of the Bi surface under conditions of weak optical excitation up to 2 mJ/cm2 incident pump fluence. The observed time constants τint of decay of diffraction spot intensity depend on the momentum transfer Δk and range from 5 to 12 ps. This large variation of τint is caused by the nonlinearity of the exponential function in the Debye–Waller factor and has to be taken into account for an intensity drop ΔI > 0.2. An analysis of more than 20 diffraction spots with a large variation in Δk gave a consistent value for the time constant τT of vibrational excitation of the surface lattice of 12 ± 1 ps independent on the excitation density. We found no evidence for a deviation from an isotropic Debye–Waller effect and conclude that the primary laser excitation leads to thermal lattice excitation, i.e., heating of the Bi surface. |
| first_indexed | 2024-12-21T13:50:52Z |
| format | Article |
| id | doaj.art-ba790007fdf94476a73c45b5be73b31b |
| institution | Directory Open Access Journal |
| issn | 2329-7778 |
| language | English |
| last_indexed | 2024-12-21T13:50:52Z |
| publishDate | 2019-05-01 |
| publisher | AIP Publishing LLC and ACA |
| record_format | Article |
| series | Structural Dynamics |
| spelling | doaj.art-ba790007fdf94476a73c45b5be73b31b2022-12-21T19:01:42ZengAIP Publishing LLC and ACAStructural Dynamics2329-77782019-05-0163035101035101-910.1063/1.5093637002903SDYUltrafast electron diffraction from a Bi(111) surface: Impulsive lattice excitation and Debye–Waller analysis at large momentum transferV. Tinnemann0C. Streubühr1B. Hafke2A. Kalus3A. Hanisch-Blicharski4M. Ligges5P. Zhou6D. von der Linde7U. Bovensiepen8M. Horn-von Hoegen9Department of Physics and Center for Nanointegration (CeNIDE), University of Duisburg-Essen, 47048 Duisburg, GermanyDepartment of Physics and Center for Nanointegration (CeNIDE), University of Duisburg-Essen, 47048 Duisburg, GermanyDepartment of Physics and Center for Nanointegration (CeNIDE), University of Duisburg-Essen, 47048 Duisburg, GermanyDepartment of Physics and Center for Nanointegration (CeNIDE), University of Duisburg-Essen, 47048 Duisburg, GermanyDepartment of Physics and Center for Nanointegration (CeNIDE), University of Duisburg-Essen, 47048 Duisburg, GermanyDepartment of Physics and Center for Nanointegration (CeNIDE), University of Duisburg-Essen, 47048 Duisburg, GermanyDepartment of Physics and Center for Nanointegration (CeNIDE), University of Duisburg-Essen, 47048 Duisburg, GermanyDepartment of Physics and Center for Nanointegration (CeNIDE), University of Duisburg-Essen, 47048 Duisburg, GermanyDepartment of Physics and Center for Nanointegration (CeNIDE), University of Duisburg-Essen, 47048 Duisburg, GermanyDepartment of Physics and Center for Nanointegration (CeNIDE), University of Duisburg-Essen, 47048 Duisburg, GermanyThe lattice response of a Bi(111) surface upon impulsive femtosecond laser excitation is studied with time-resolved reflection high-energy electron diffraction. We employ a Debye–Waller analysis at large momentum transfer of 9.3 Å−1 ≤ Δ k ≤ 21.8 Å−1 in order to study the lattice excitation dynamics of the Bi surface under conditions of weak optical excitation up to 2 mJ/cm2 incident pump fluence. The observed time constants τint of decay of diffraction spot intensity depend on the momentum transfer Δk and range from 5 to 12 ps. This large variation of τint is caused by the nonlinearity of the exponential function in the Debye–Waller factor and has to be taken into account for an intensity drop ΔI > 0.2. An analysis of more than 20 diffraction spots with a large variation in Δk gave a consistent value for the time constant τT of vibrational excitation of the surface lattice of 12 ± 1 ps independent on the excitation density. We found no evidence for a deviation from an isotropic Debye–Waller effect and conclude that the primary laser excitation leads to thermal lattice excitation, i.e., heating of the Bi surface.http://dx.doi.org/10.1063/1.5093637 |
| spellingShingle | V. Tinnemann C. Streubühr B. Hafke A. Kalus A. Hanisch-Blicharski M. Ligges P. Zhou D. von der Linde U. Bovensiepen M. Horn-von Hoegen Ultrafast electron diffraction from a Bi(111) surface: Impulsive lattice excitation and Debye–Waller analysis at large momentum transfer Structural Dynamics |
| title | Ultrafast electron diffraction from a Bi(111) surface: Impulsive lattice excitation and Debye–Waller analysis at large momentum transfer |
| title_full | Ultrafast electron diffraction from a Bi(111) surface: Impulsive lattice excitation and Debye–Waller analysis at large momentum transfer |
| title_fullStr | Ultrafast electron diffraction from a Bi(111) surface: Impulsive lattice excitation and Debye–Waller analysis at large momentum transfer |
| title_full_unstemmed | Ultrafast electron diffraction from a Bi(111) surface: Impulsive lattice excitation and Debye–Waller analysis at large momentum transfer |
| title_short | Ultrafast electron diffraction from a Bi(111) surface: Impulsive lattice excitation and Debye–Waller analysis at large momentum transfer |
| title_sort | ultrafast electron diffraction from a bi 111 surface impulsive lattice excitation and debye waller analysis at large momentum transfer |
| url | http://dx.doi.org/10.1063/1.5093637 |
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