Femtosecond x-ray scattering in condensed matter [Elektronische Ressource] / von Clemens von Korff Schmising

Femtosecond X-Ray Scattering in CondensedMatterDISSERTATIONzur Erlangung des akademischen Gradesdoctor rerum naturalium(Dr. rer. nat.)im Fach Physikeingereicht an derMathematisch-Naturwissenschaftlichen Fakultät IHumboldt-Universität zu BerlinvonHerr Dipl.-Phys. Clemens von Korff Schmisinggeboren am 20.07.1977 in BonnPräsident der Humboldt-Universität zu Berlin:Prof. Dr. Dr. h.c. Christoph MarkschiesDekan der Mathematisch-Naturwissenschaftlichen Fakultät I:Prof. Dr. Lutz-Helmut SchönGutachter:1. Prof. Dr. Thomas Elsässer2. Prof. Dr. Oliver Benson3. Prof. Dr. Martin Wolfeingereicht am: 7. Juli 2008Tag der mündlichen Prüfung: 24. November 2008AbstractThis thesis investigates the manifold couplings between electronic andstructural properties in crystalline Perovskite oxides and a polar molecularcrystal. Ultrashort optical excitation changes the electronic structure andthe dynamics of the connected reversible lattice rearrangement is imaged inreal time by femtosecond X-ray scattering experiments.An epitaxially grown superlattice consisting of alternating nanolayers ofmetallic and ferromagnetic strontium ruthenate (SRO) and dielectric stron-tium titanate serves as a model system to study optically generated stress.In the ferromagnetic phase, phonon-mediated and magnetostrictive stress inSRO display similar sub-picosecond dynamics, similar strengths but oppositesign and different excitation spectra.