# FS-PS

 2019-02-2213:12 [PUBDB-2019-01222] Journal Article et al Superradiance of an ensemble of nuclei excited by a free electron laser Nature physics 14(3), 261 - 264 (2018) [10.1038/s41567-017-0001-z]   In 1954 Dicke predicted the accelerated initial decay of multiple atomic excitations1, laying the foundation for the concept of superradiance. Further studies$^{2,3,4}$ suggested that emission of the total energy was similarly accelerated, provided that the system reaches the inversion threshold. [...] Restricted: PDF PDF (PDFA); 2019-02-1809:39 [PUBDB-2019-01133] Journal Article et al Engineering ferroelectric instability to achieve ultralow thermal conductivity and high thermoelectric performance in $\mathrm{Sn_{1−x}Ge_{x}Te}$ Energy & environmental science 12(2), 589 - 595 (2019) [10.1039/C8EE03162B]   High thermoelectric performance of a crystalline solid requires it to have low thermal conductivity which is one of the utmost material challenges. Herein, we demonstrate how the local structural distortions and the associated ferroelectric lattice instability induced soft polar phonons effectively scatter the heat carrying acoustic phonons and help achieve ultralow lattice thermal conductivity in SnTe by engineering the instability near room temperature via Ge (x = 0–30 mol%) alloying. [...] Restricted: PDF PDF (PDFA); External link: Fulltext 2019-01-2915:40 [PUBDB-2019-00851] Book/Report/Dissertation / PhD Thesis Wurth, W. Diffraction anomalous fine structure in Laue geometry [DESY-THESIS-2018-043] Hamburg : Verlag Deutsches Elektronen-Synchrotron, DESY-THESIS 108 pp. (2016) [10.3204/PUBDB-2019-00851] = Dissertation, Universität Hamburg, 2016   This thesis deals with the further development of the method of Borrmannspectroscopy and the development of the novel method of diffractionanomalous fine structure in Laue geometry.Borrmann spectroscopy utilizes the Borrmann effect in order to enhancethe quadrupol absorption, which enables studying weak quadrupoltransitions. In the present work a model is developed, which describes thedependence of the quadrupol enhancement on temperature and anisotropyof the chemical environment. [...] OpenAccess: desy-thesis-18-043.title - PDF PDF (PDFA); Laurus_dissertation - PDF PDF (PDFA); 2019-01-1616:27 [PUBDB-2019-00538] Journal Article et al Pressure-induced amorphization in plagioclase feldspars: A time-resolved powder diffraction study during rapid compression Earth and planetary science letters 507, 166 - 174 (2019) [10.1016/j.epsl.2018.11.038]   The pressure-induced amorphization of the two endmembers of the plagioclase ((Na$_{1−x}$Cax)Al$_{1+x}$Si$_{3−x}$O$_8$) solid-solution, anorthite (CaAl$_2$Si$_2$O$_8$) and albite (NaAlSi$_3$O$_8$), has been studied as a function of compression rate by means of time-resolved powder diffraction. Anorthite and albite were compressed in a diamond anvil cell to 80 GPa at multiple rates from 0.05 GPa/s to 80 GPa/s. [...] 2019-01-1014:47 [PUBDB-2019-00321] Journal Article et al Correction of axial position uncertainty and systematic detector errors in ptychographic diffraction imaging Optical engineering 57(08), 084106 (2018) [10.1117/1.OE.57.8.084106]   Ptychography is a diffraction imaging method that allows one to solve inverse problems in microscopy with the ability to retrieve information about and correct for systematic errors. Here, we propose techniques to correct for axial position uncertainty, detector point spread, and inhomogeneous detector response using ptychography’s inherent self-calibration capabilities [...] OpenAccess: PDF PDF (PDFA); 2019-01-1014:34 [PUBDB-2019-00315] Journal Article et al Atomic-layer-resolved composition and electronic structure of the cuprate $\mathrm{Bi_{2}Sr_{2}CaCu_{2}O_{8+δ}}$ from soft x-ray standing-wave photoemission Physical review / B 98(15), 155133 (2018) [10.1103/PhysRevB.98.155133]   A major remaining challenge in the superconducting cuprates is the unambiguous differentiation of thecomposition and electronic structure of the CuO$_2$ layers and those of the intermediate layers. The large caxis for these materials permits employing soft x-ray (930.3 eV) standing wave (SW) excitation in photoemissionthat yields atomic layer-by-layer depth resolution of these properties. [...] OpenAccess: PDF PDF (PDFA); External link: Fulltext 2019-01-1014:26 [PUBDB-2019-00311] Journal Article et al Software Platform for European XFEL: Towards Online Experimental Data Analysis Lobachevskii journal of mathematics 39(9), 1170 - 1178 (2018) [10.1134/S1995080218090093] special issue: "High Performance Data Intensive Computing"   Large amount of data being generated at large scale facilities like European X-ray Free-Electron Laser (XFEL) requires new approaches for data processing and analysis. One of the mostcomputationally challenging experiments at an XFEL is single-particle structure determination.In this paper we propose a new design for an integrated software platform which combines well establishedtechniques for XFEL data analysis with High Performance Data Analysis (HPDA)methods. [...] Published on 2019-01-08. Available in OpenAccess from 2020-01-08.: PDF PDF (PDFA); Restricted: PDF PDF (PDFA); External link: Fulltext 2019-01-0911:10 [PUBDB-2019-00169] Journal Article et al Correction: Surface induced smectic order in ionic liquids – an X-ray reflectivity study of $[C_{22}C_{1}im]^{+}[NTf_{2}]^{−}$ Physical chemistry, chemical physics 20(37), 24494 - 24495 (2018) [10.1039/C8CP91851A]   Surface induced smectic order was found for the ionic liquid 1-methyl-3-docosylimidazolium bis(trifluoromethlysulfonyl)imide by X-ray reflectivity and grazing incidence scattering experiments. Near the free liquid surface, an ordered structure of alternating layers composed of polar and non-polar moieties is observed. [...] OpenAccess: PDF PDF (PDFA); 2019-01-0814:42 [PUBDB-2019-00124] Journal Article et al Efficient charge generation from triplet excitons in metal-organic heterojunctions Physical review / B 99(2), 020303 (2019) [10.1103/PhysRevB.99.020303]   The success of many emerging molecular electronics concepts hinges on an atomistic understanding of the underlying electronic dynamics. We employ picosecond time-resolved x-ray photoemission spectroscopy (tr-XPS) to elucidate the roles of singlet and triplet excitons for photoinduced charge generation at a copper-phthalocyanine–C$_{60}$ heterojunction [...] OpenAccess: PDF PDF (PDFA); External link: Fulltext 2019-01-0810:17 [PUBDB-2019-00094] Journal Article et al Evidence of a first-order smectic-hexatic transition and its proximity to a tricritical point in smectic films Physical review / E 98(5), 052703 (2018) [10.1103/PhysRevE.98.052703]   Experimental and theoretical studies of a smectic-A–hexatic-B transition in freely suspended films of thickness 2 –10 $μm$ of the n-pentyl-4′−n-pentanoyloxy-biphenyl-4-carboxylate (54COOBC) compound are presented. X-ray investigations revealed a discontinuous first-order transition into the hexatic phase [...] OpenAccess: PDF PDF (PDFA);