TY  - GEN
A1  - Pudell, Jan-Etienne
A1  - Maznev, Alexei
A1  - Herzog, Marc
A1  - Kronseder, M.
A1  - Back, Christian
A1  - Malinowski, Gregory
A1  - von Reppert, Alexander
A1  - Bargheer, Matias
T1  - Layer specific observation of slow thermal equilibration in ultrathin metallic nanostructures by femtosecond X-ray diffraction
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Ultrafast heat transport in nanoscale metal multilayers is of great interest in the context of optically induced demagnetization, remagnetization and switching. If the penetration depth of light exceeds the bilayer thickness, layer-specific information is unavailable from optical probes. Femtosecond diffraction experiments provide unique experimental access to heat transport over single digit nanometer distances. Here, we investigate the structural response and the energy flow in the ultrathin double-layer system: gold on ferromagnetic nickel. Even though the excitation pulse is incident from the Au side, we observe a very rapid heating of the Ni lattice, whereas the Au lattice initially remains cold. The subsequent heat transfer from Ni to the Au lattice is found to be two orders of magnitude slower than predicted by the conventional heat equation and much slower than electron-phonon coupling times in Au. We present a simplified model calculation highlighting the relevant thermophysical quantities.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 797 
KW  - thin magnetic layers
KW  - optical-excitation
KW  - heat-capacity
KW  - electron
KW  - gold
KW  - dynamics
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426233
SN  - 1866-8372
IS  - 797
ER  - 
TY  - GEN
A1  - Zeuschner, Steffen
A1  - Parpiiev, Tymur
A1  - Pezeril, Thomas
A1  - Hillion, Arnaud
A1  - Dumesnil, Karine
A1  - Anane, Abdelmadjid
A1  - Pudell, Jan-Etienne
A1  - Willig, Lisa
A1  - Rössle, Matthias
A1  - Herzog, Marc
A1  - von Reppert, Alexander
A1  - Bargheer, Matias
T1  - Tracking picosecond strain pulses in heterostructures that exhibit giant magnetostriction
T2  - Postprints der Universität Potsdam : Mathematisch-naturwissenschaftliche Reihe
N2  - We combine ultrafast X-ray diffraction (UXRD) and time-resolved Magneto-Optical Kerr Effect (MOKE) measurements to monitor the strain pulses in laser-excited TbFe2/Nb heterostructures. Spatial separation of the Nb detection layer from the laser excitation region allows for a background-free characterization of the laser-generated strain pulses. We clearly observe symmetric bipolar strain pulses if the excited TbFe2 surface terminates the sample and a decomposition of the strain wavepacket into an asymmetric bipolar and a unipolar pulse, if a SiO2 glass capping layer covers the excited TbFe2 layer. The inverse magnetostriction of the temporally separated unipolar strain pulses in this sample leads to a MOKE signal that linearly depends on the strain pulse amplitude measured through UXRD. 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.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 706 
KW  - Heterostructures
KW  - Magnetooptical effects
KW  - Metal oxides
KW  - Crystal lattices
KW  - Transition metals
KW  - Magnetism
KW  - Ultrafast X-ray diffraction
KW  - Lasers
KW  - Bragg peak
KW  - Phonons
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-428457
SN  - 1866-8372
IS  - 706
ER  -