@article{NavirianHerzogGoldshteynetal.2011, author = {Navirian, Hengameh A. and Herzog, Marc and Goldshteyn, J. and Leitenberger, Wolfram and Vrejoiu, Ionella and Khakhulin, D. and Wulff, M. and Shayduk, Roman and Gaal, P. and Bargheer, Matias}, title = {Shortening x-ray pulses for pump-probe experiments at synchrotrons}, series = {Journal of applied physics}, volume = {109}, journal = {Journal of applied physics}, number = {12}, publisher = {American Institute of Physics}, address = {Melville}, issn = {0021-8979}, doi = {10.1063/1.3601057}, pages = {3}, year = {2011}, abstract = {We implemented an experimental scheme for ultrafast x-ray diffraction at storage rings based on a laser-driven Bragg-switch that shortens the x-ray pulses emitted from an undulator. The increased time-resolution is demonstrated by observing changes of intensity, position and width of the diffraction peaks of a La(0.7)Sr(0.3)MnO(3)/SrTiO(3) superlattice sample after optical excitation, i.e., by quantitatively measuring the propagation of an expansion wave through the sample. These experimental transients with timescales of 35 to 60 ps evidence a reduction of the x-ray pulse duration by a factor of two.}, language = {en} } @article{ShaydukNavirianLeitenbergeretal.2011, author = {Shayduk, Roman and Navirian, Hengameh and Leitenberger, Wolfram and Goldshteyn, Jevgenij and Vrejoiu, Ionela and Weinelt, Martin and Gaal, Peter and Herzog, Marc and von Korff Schmising, Clemens and Bargheer, Matias}, title = {Nanoscale heat transport studied by high-resolution time-resolved x-ray diffraction}, series = {New journal of physics : the open-access journal for physics}, volume = {13}, journal = {New journal of physics : the open-access journal for physics}, number = {11}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {1367-2630}, doi = {10.1088/1367-2630/13/9/093032}, pages = {11}, year = {2011}, abstract = {We report on synchrotron-based high-repetition rate ultrafast x-ray diffraction (UXRD) experiments monitoring the transport of heat from an epitaxial La(0.7)Sr(0.3)MnO(3)/SrTiO(3) superlattice (SL) into the substrate on timescales from 100 ps to 4 mu s. Transient thermal lattice expansion was determined with an accuracy of 10(-7), corresponding to a sensitivity to temperature changes down to 0.01 K. We follow the heat flow within the SL and into the substrate after the impulsive laser heating leads to a small temperature rise of Delta T = 6 K. The transient lattice temperature can be simulated very well using the bulk heat conductivities. This contradicts the interpretation of previous UXRD measurements, which predicted a long-lasting expansion of SrRuO(3) for more than 200 ps. The disagreement could be resolved by assuming that the heat conductivity changes in the first hundred picoseconds.}, language = {en} }