title: Ultrafast lattice response of photoexcited thin films studied by X-ray diffraction.
abstract: Using ultrafast X-ray diffraction, we study the coherent picosecond lattice dynamics of photoexcited thin films in the two limiting cases, where the photoinduced stress profile decays on a length scale larger and smaller than the film thickness. We solve a unifying analytical model of the strain propagation for acoustic impedance-matched opaque films on a semi-infinite transparent substrate, showing that the lattice dynamics essentially depend on two parameters: One for the spatial profile and one for the amplitude of the strain. We illustrate the results by comparison with high-quality ultrafast X-ray diffraction data of SrRuO3 films on SrTiO3 substrates.
authors.forename: Daniel
authors.identifier: 0000-0001-7988-6489
authors.initials: D
authors.lastname: Schick
authors.forename: Marc
authors.initials: M
authors.lastname: Herzog
authors.affiliation: Institut für Physik und Astronomie, Universität Potsdam , Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Bojahr
authors.affiliation: Institut für Physik und Astronomie, Universität Potsdam , Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany.
authors.forename: Wolfram
authors.initials: W
authors.lastname: Leitenberger
authors.affiliation: Bundesanstalt für Materialforschung und -prüfung , Unter den Eichen 87, 12205 Berlin, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hertwig
authors.forename: Roman
authors.identifier: 0000-0001-7731-222X
authors.initials: R
authors.lastname: Shayduk
authors.forename: Matias
authors.initials: M
authors.lastname: Bargheer