Electron-lattice energy relaxation in laser-excited thin-film Au-insulator heterostructures studied by ultrafast MeV electron diffraction

K. Sokolowski-Tinten; X. Shen; Q. Zheng; T. Chase; R. Coffee; M. Jerman; R. K. Li; M. Ligges; I. Makasyuk; M. Mo; A. H. Reid; B. Rethfeld; T. Vecchione; S. P. Weathersby; H. A. Dürr; X. J. Wang

doi:10.1063/1.4995258

Structural Dynamics (Sep 2017)

Electron-lattice energy relaxation in laser-excited thin-film Au-insulator heterostructures studied by ultrafast MeV electron diffraction

K. Sokolowski-Tinten,
X. Shen,
Q. Zheng,
T. Chase,
R. Coffee,
M. Jerman,
R. K. Li,
M. Ligges,
I. Makasyuk,
M. Mo,
A. H. Reid,
B. Rethfeld,
T. Vecchione,
S. P. Weathersby,
H. A. Dürr,
X. J. Wang

Affiliations

K. Sokolowski-Tinten: Faculty of Physics and Centre for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg, Germany
X. Shen: SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025, USA
Q. Zheng: School of Materials and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, China
T. Chase: SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025, USA
R. Coffee: SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025, USA
M. Jerman: Faculty of Physics and Centre for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg, Germany
R. K. Li: SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025, USA
M. Ligges: Faculty of Physics and Centre for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg, Germany
I. Makasyuk: SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025, USA
M. Mo: SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025, USA
A. H. Reid: SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025, USA
B. Rethfeld: Department of Physics and OPTIMAS Research Center, Technical University Kaiserslautern, Erwin-Schrödinger-Strae 46, 67663 Kaiserslautern, Germany
T. Vecchione: SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025, USA
S. P. Weathersby: SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025, USA
H. A. Dürr: SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025, USA
X. J. Wang: SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025, USA

DOI: https://doi.org/10.1063/1.4995258
Journal volume & issue: Vol. 4, no. 5
pp. 054501 – 054501-8

Abstract

Read online

We apply time-resolved MeV electron diffraction to study the electron-lattice energy relaxation in thin film Au-insulator heterostructures. Through precise measurements of the transient Debye-Waller-factor, the mean-square atomic displacement is directly determined, which allows to quantitatively follow the temporal evolution of the lattice temperature after short pulse laser excitation. Data obtained over an extended range of laser fluences reveal an increased relaxation rate when the film thickness is reduced or the Au-film is capped with an additional insulator top-layer. This behavior is attributed to a cross-interfacial coupling of excited electrons in the Au film to phonons in the adjacent insulator layer(s). Analysis of the data using the two-temperature-model taking explicitly into account the additional energy loss at the interface(s) allows to deduce the relative strength of the two relaxation channels.

Published in Structural Dynamics

ISSN: 2329-7778 (Online)
Publisher: AIP Publishing LLC and ACA
Country of publisher: United States
LCC subjects: Science: Chemistry: Crystallography
Website: http://sd.aip.org

About the journal