DPG Phi
Verhandlungen
Verhandlungen
DPG

Dresden 2017 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

KR: Fachgruppe Kristallographie

KR 3: Crystallography - poster session

KR 3.3: Poster

Wednesday, March 22, 2017, 18:00–20:00, P4

Watching the Verwey transition of Magnetite by Timeresolved X-Ray diffraction — •Alexander von Reppert1, Jan-Etienne Pudell1, Flavio Zamponi1, Azize Koc2, Stephan Geprägs3, Jose Emilio Lorenzo4, Luc Ortega5, Matthias Reinhardt2, and Matias Bargheer1,21Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht Str. 24-25, 14476 Potsdam, Germany — 2Helmholtz-Zentrum Berlin BESSY II, Albert-Einstein Str. 15, 12489 Berlin, Germany — 3Walther-Meißner-Institut, Bayerische Akademie d. Wissenschaften, 85748 Garching, Germany — 4Institut Nèel, CNRS & Univ. Grenoble Alpes, 38042 Grenoble, France — 5Laboratoire de Physique des Solides, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay, France

We present timeresolved X-Ray diffraction from a 300 nm thin Magnetite(Fe3O4) film that is driven across the Verwey transition by fs-laser excitation. The prototypical insulator to metal transition at 123 K is accompanied by a peak intensity increase and peak width decrease of structural Bragg peaks, which we attribute to the destruction of trimerons that lead to inhomogeneous lattice strain in the low T phase. Our systematic investigations of the lattice dynamics yield two timescales: An ultrafast peak width drop - probably due to electronic processes - which is subsequently enhanced by transport and equilibration of the excitations. Complementary to our lab-based Plasma X-Ray source we conducted measurements at the XPP beamline at the synchrotron BESSY II where we observe that the recovery timescale depends crucially on the proximity to the transition temperature.

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 2017 > Dresden