Browsing by Author "Hansen, TC"

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    In situ characterization of a Nb and Mo containing γ-TiAl based alloy using neutron diffraction and high-temperature microscopy
    (Wiley-VCH Verlag Berlin, 2009-11) Watson, IJ; Liss, KD; Clemens, H; Wallgram, W; Schmoelzer, T; Hansen, TC; Reid, M
    In recent times, novel titanium aluminides containing the bcc β-phase at high temperatures are being developed for improved hot-working capabilities, however, predictions of the phase diagrams are merely uncertain. Here we present in-situ neutron studies, which are particularly sensitive to the atomic disorder in the ordered phases. Complementary laser scanning confocal microscopy is employed for in-situ microstructural investigations. © 2009, Wiley-VCH Verlag Berlin
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    In situ neutron diffraction under high pressure-Providing an insight into working catalysts
    (Elsevier, 2012-05-01) Kandemir, T; Wallacher, D; Hansen, TC; Liss, KD; d'Alnoncourt, RN; Schlogl, R; Behrens, M
    In the present work the construction and application of a continuous flow cell is presented, from which neutron diffraction data could be obtained during catalytic reactions at high pressure. By coupling an online gas detection system, parallel structure and activity investigations of working catalysts under industrial relevant conditions are possible. The flow cell can be operated with different feed gases in a wide range from room temperature to 603 K. Pressures from ambient up to 6 MPa are applicable. An exchangeable sample positioning system makes the flow cell suitable for several different goniomter types on a variety of instrument beam lines. Complementary operational test measurements were carried out monitoring reduction of and methanol synthesis over a Cu/ZnO/Al2O3 catalyst at the high-flux powder diffraction beamline D1B at ILL and high-resolution diffraction beamline Echidna at ANSTO. (C) 2012 Elsevier B.V.
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    In-situ study of catalytic processes: neutron diffraction of a methanol synthesis catalyst at industrially relevant pressure
    (Wiley-V C H Verlag GMBH, 2013-01-01) Kandemir, T; Girgsdies, F; Hansen, TC; Liss, KD; Kasatkin, I; Kunkes, EL; Wowsnick, G; Jacobsen, N; Schlögl, R; Behrens, M
    An industrial methanol synthesis catalyst operating at high pressure was studied by in situ neutron diffraction. The peculiar microstructure of Cu/ZnO/Al2O3 nanocatalysts was found to be stable under reaction conditions. Stacking fault annealing and brass formation was only observed at temperatures higher than used in the methanol synthesis process, providing support for active role of defects in this catalyst system. © 2013, Wiley-VCH Verlag.