Regensburg 2019 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 15: Magnetism Poster A
MA 15.52: Poster
Dienstag, 2. April 2019, 10:00–13:00, Poster E
Monitoring picosecond strain pulse echos in magnetostrictive heterostructures — •Steffen Peer Zeuschner1,2, Tymur Parpiiev3, Thomas Pezeril3, Jan-Etienne Pudell2, Marc Herzog2, Alexander von Reppert2, and Matias Bargheer1,2 — 1Helmholtz-Zentrum Berlin, BESSY II, Berlin, Germany — 2Institut für Physik und Astronomie, University of Potsdam, Potsdam, Germany — 3Institut des Molécules et Matériaux du Mans (UMR CNRS 6283), Université du Maine, Le Mans cedex, France
We investigate picosecond strain pulses in laser-excited highly magnetostrictive TbFe2/Nb heterostructures with time-resolved magneto-optical Kerr-effect (MOKE) probing and ultrafast X-ray diffraction (UXRD). Burying the Nb layer underneath the laser excitation region in TbFe2 allows for a heat-background free characterization of the laser-generated strain pulses. We clearly observe a decomposition of the strain transient into an asymmetric bipolar and a unipolar pulse, when an amorphous SiO2 capping layer covers the excited TbFe2. The inverse magnetostriction of the temporally separated unipolar strain pulses leads to a MOKE signal from the TbFe2 surface that linearly depends on the strain pulse amplitude, giving an estimate of the magneto-acoustic coupling strength. Linear chain model simulations accurately predict the timing and shape of UXRD and MOKE signals that are caused by the strain reflections from multiple interfaces in the heterostructure. A second excitation pulse allows the construction of an inverted bipolar strain pulse which is expected to exhibit drastically different nonlinear acoustic propagation.