TY  - JOUR
A1  - Schick, Daniel
A1  - Shayduk, Roman
A1  - Bojahr, Andre
A1  - Herzog, Marc
A1  - von Korff Schmising, Clemens
A1  - Gaal, Peter
A1  - Bargheer, Matias
T1  - Ultrafast reciprocal-space mapping with a convergent beam
JF  - JOURNAL OF APPLIED CRYSTALLOGRAPHY
N2  - A diffractometer setup is presented, based on a laser-driven plasma X-ray source for reciprocal-space mapping with femtosecond temporal resolution. In order to map out the reciprocal space, an X-ray optic with a convergent beam is used with an X-ray area detector to detect symmetrically and asymmetrically diffracted X-ray photons simultaneously. The setup is particularly suited for measuring thin films or imperfect bulk samples with broad rocking curves. For quasi-perfect crystalline samples with insignificant in-plane Bragg peak broadening, the measured reciprocal-space maps can be corrected for the known resolution function of the diffractometer in order to achieve high-resolution rocking curves with improved data quality. In this case, the resolution of the diffractometer is not limited by the convergence of the incoming X-ray beam but is solely determined by its energy bandwidth.
Y1  - 2013
U6  - https://doi.org/10.1107/S0021889813020013
SN  - 0021-8898
VL  - 46
IS  - 10
SP  - 1372
EP  - 1377
PB  - WILEY-BLACKWELL
CY  - HOBOKEN
ER  - 
TY  - JOUR
A1  - Shayduk, Roman
A1  - Herzog, Marc
A1  - Bojahr, Andre
A1  - Schick, Daniel
A1  - Gaal, Peter
A1  - Leitenberger, Wolfram
A1  - Navirian, Hengameh
A1  - Sander, Mathias
A1  - Goldshteyn, Jevgenij
A1  - Vrejoiu, Ionela
A1  - Bargheer, Matias
T1  - Direct time-domain sampling of subterahertz coherent acoustic phonon spectra in SrTiO3 using ultrafast x-ray diffraction
JF  - Physical review : B, Condensed matter and materials physics
N2  - We synthesize sub-THz longitudinal quasimonochromatic acoustic phonons in a SrTiO3 single crystal using a SrRuO3/SrTiO3 superlattice as an optical-acoustic transducer. The generated acoustic phonon spectrum is determined using ultrafast x-ray diffraction. The analysis of the generated phonon spectrum in the time domain reveals a k-vector dependent phonon lifetime. It is observed that even at sub-THz frequencies the phonon lifetime agrees with the 1/omega(2) power law known from Akhiezer's model for hyper sound attenuation. The observed shift of the synthesized spectrum to the higher q is discussed in the framework of nonlinear effects appearing due to the high amplitude of the synthesized phonons.
Y1  - 2013
U6  - https://doi.org/10.1103/PhysRevB.87.184301
SN  - 1098-0121
VL  - 87
IS  - 18
PB  - American Physical Society
CY  - College Park
ER  -