TY  - GEN
A1  - Schick, Daniel
A1  - Eckert, Sebastian
A1  - Pontius, Niko
A1  - Mitzner, Rolf
A1  - Föhlisch, Alexander
A1  - Holldack, Karsten
A1  - Sorgenfrei, Florian
T1  - Versatile soft X-ray-optical cross-correlator for ultrafast applications
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - We present an X-ray-optical cross-correlator for the soft (> 150 eV) up to the hard X-ray regime based on a molybdenum-silicon superlattice. The cross-correlation is done by probing intensity and position changes of superlattice Bragg peaks caused by photoexcitation of coherent phonons. This approach is applicable for a wide range of X-ray photon energies as well as for a broad range of excitation wavelengths and requires no external fields or changes of temperature. Moreover, the cross-correlator can be employed on a 10 ps or 100 fs time scale featuring up to 50% total X-ray reflectivity and transient signal changes of more than 20%. (C) 2016 Author(s).
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1331 
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-436962
SN  - 1866-8372
IS  - 1331
SP  - 054304-1
EP  - 054304-8
ER  - 
TY  - GEN
A1  - Eckert, Sebastian
A1  - Miedema, Piter
A1  - Quevedo, Wilson
A1  - O'Cinneide, B.
A1  - Fondell, Mattis
A1  - Beye, Martin
A1  - Pietzsch, Annette
A1  - Ross, Matthew R.
A1  - Khalil, Munira
A1  - Föhlisch, Alexander
T1  - Molecular structures and protonation state of 2-Mercaptopyridine in aqueous solution
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The speciation of 2-Mercaptopyridine in aqueous solution has been investigated with nitrogen 1s Near Edge X-ray Absorption Fine Structure spectroscopy and time dependent Density Functional Theory. The prevalence of distinct species as a function of the solvent basicity is established. No indications of dimerization towards high concentrations are found. The determination of different molecular structures of 2-Mercaptopyridine in aqueous solution is put into the context of proton-transfer in keto-enol and thione-thiol tautomerisms. (C) 2016 The Authors. Published by Elsevier B.V.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 953 
KW  - ray-emission-spectroscopy
KW  - x-ray
KW  - hydroxypyridine-pyridone
KW  - protomeric equilibria
KW  - self-association
KW  - CU(110)
KW  - valence
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-437473
SN  - 1866-8372
IS  - 953
SP  - 103
EP  - 106
ER  - 
TY  - GEN
A1  - Niskanen, Johannes
A1  - Kooser, Kuno
A1  - Koskelo, Jaakko
A1  - Käämbre, Tanel
A1  - Kunnus, Kristjan
A1  - Pietzsch, Annette
A1  - Quevedo, Wilson
A1  - Hakala, Mikko
A1  - Föhlisch, Alexander
A1  - Huotari, Simo
A1  - Kukk, Edwin
T1  - Density functional simulation of resonant inelastic X-ray scattering experiments in liquids: acetonitrile
N2  - In this paper we report an experimental and computational study of liquid acetonitrile (H3C–C[triple bond, length as m-dash]N) by resonant inelastic X-ray scattering (RIXS) at the N K-edge. The experimental spectra exhibit clear signatures of the electronic structure of the valence states at the N site and incident-beam-polarization dependence is observed as well. Moreover, we find fine structure in the quasielastic line that is assigned to finite scattering duration and nuclear relaxation. We present a simple and light-to-evaluate model for the RIXS maps and analyze the experimental data using this model combined with ab initio molecular dynamics simulations. In addition to polarization-dependence and scattering-duration effects, we pinpoint the effects of different types of chemical bonding to the RIXS spectrum and conclude that the H2C–C[double bond, length as m-dash]NH isomer, suggested in the literature, does not exist in detectable quantities. We study solution effects on the scattering spectra with simulations in liquid and in vacuum. The presented model for RIXS proved to be light enough to allow phase-space-sampling and still accurate enough for identification of transition lines in physical chemistry research by RIXS.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 331 
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-395133
ER  -