TY  - JOUR
A1  - Schick, Daniel
A1  - Herzog, Marc
A1  - Bojahr, Andre
A1  - Leitenberger, Wolfram
A1  - Hertwig, Andreas
A1  - Shayduk, Roman
A1  - Bargheer, Matias
T1  - Ultrafast lattice response of photoexcited thin films studied by X-ray diffraction
JF  - Structural dynamics
N2  - Using ultrafast X-ray diffraction, we study the coherent picosecond lattice dynamics of photoexcited thin films in the two limiting cases, where the photoinduced stress profile decays on a length scale larger and smaller than the film thickness. We solve a unifying analytical model of the strain propagation for acoustic impedance-matched opaque films on a semi-infinite transparent substrate, showing that the lattice dynamics essentially depend on two parameters: One for the spatial profile and one for the amplitude of the strain. We illustrate the results by comparison with high-quality ultrafast X-ray diffraction data of SrRuO3 films on SrTiO3 substrates. (C) 2014 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.
Y1  - 2014
U6  - https://doi.org/10.1063/1.4901228
SN  - 2329-7778
VL  - 1
IS  - 6
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Gaal, Peter
A1  - Schick, Daniel
A1  - Herzog, Marc
A1  - Bojahr, Andre
A1  - Shayduk, Roman
A1  - Goldshteyn, Jevgeni
A1  - Leitenberger, Wolfram
A1  - Vrejoiu, Ionela
A1  - Khakhulin, Dmitry
A1  - Wulff, Michael
A1  - Bargheer, Matias
T1  - Ultrafast switching of hard X-rays
JF  - Journal of synchrotron radiation
N2  - A new concept for shortening hard X-ray pulses emitted from a third-generation synchrotron source down to few picoseconds is presented. The device, called the PicoSwitch, exploits the dynamics of coherent acoustic phonons in a photo-excited thin film. A characterization of the structure demonstrates switching times of <= 5 ps and a peak reflectivity of similar to 10(-3). The device is tested in a real synchrotron-based pump-probe experiment and reveals features of coherent phonon propagation in a second thin film sample, thus demonstrating the potential to significantly improve the temporal resolution at existing synchrotron facilities.
KW  - ultrafast X-ray diffraction
KW  - thin film
KW  - coherent phonons
KW  - X-ray switching
KW  - pulse shortening
KW  - optical pump X-ray probe
KW  - time-resolved
Y1  - 2014
U6  - https://doi.org/10.1107/S1600577513031949
SN  - 0909-0495
SN  - 1600-5775
VL  - 21
SP  - 380
EP  - 385
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Navirian, Hengameh A.
A1  - Schick, Daniel
A1  - Gaal, Peter
A1  - Leitenberger, Wolfram
A1  - Shayduk, Roman
A1  - Bargheer, Matias
T1  - Thermoelastic study of nanolayered structures using time-resolved X-ray diffraction at high repetition rate
JF  - Applied physics letters
N2  - We investigate the thermoelastic response of a nanolayered sample composed of a metallic SrRuO3 electrode sandwiched between a ferroelectric Pb(Zr0.2Ti0.8)O-3 film with negative thermal expansion and a SrTiO3 substrate. SrRuO3 is rapidly heated by fs-laser pulses with 208 kHz repetition rate. Diffraction of X-ray pulses derived from a synchrotron measures the transient out-of-plane lattice constant c of all three materials simultaneously from 120 ps to 5 mu s with a relative accuracy up to Delta c/c = 10(-6). The in-plane propagation of sound is essential for understanding the delayed out-of-plane compression of Pb(Zr0.2Ti0.8)O-3.
Y1  - 2014
U6  - https://doi.org/10.1063/1.4861873
SN  - 0003-6951
SN  - 1077-3118
VL  - 104
IS  - 2
PB  - American Institute of Physics
CY  - Melville
ER  -