Speaker
Philipp Wessels
(The Hamburg Centre for Ultrafast Imaging, Universität Hamburg)
Description
Oral presentation (~ 20 minutes)
Abstract:
Picosecond magnetization dynamics of small permalloy (Ni80Fe20) elements has been investigated with a new full-field transmission microscope at the soft X-ray beamline P04 of the high brilliance synchrotron radiation source PETRA III.
The soft X-ray microscope generates a flat-top illumination field of 20 µm diameter using a grating condenser. A tilted nanostructured magnetic sample can be excited either by making use of a mobile synchronized femtosecond laser system or by a picosecond electric current pulse via a coplanar waveguide. The transmitted light of the sample plane is directly imaged by a micro zone plate with < 65 nm resolution onto a 2D gateable X-ray detector to select one particular bunch in the storage ring that probes the time evolution of the dynamic information successively via XMCD spectromicroscopy in a pump-probe scheme.
In the experiments it was possible to generate a homogeneously magnetized state in patterned magnetic layers by a strong magnetic Oersted field pulse and directly observe the destruction and recovery of the initial flux-closure vortex domain patterns. On the rising edge of the magnetic field pulse, high velocities of a central vortex core were discovered exceeding 1 km/s.
Primary author
Philipp Wessels
(The Hamburg Centre for Ultrafast Imaging, Universität Hamburg)
Co-authors
Dr
Andreas Vogel
(Institute for Applied Physics, Universität Hamburg)
Mr
Gennaro Abbati
(Institute for X-Optics, Hochschule Koblenz)
Dr
Guido Meier
(Institute for Applied Physics)
Dr
Jens Viefhaus
(Deutsches Elektronen-Synchrotron)
Mr
Johannes Ewald
(Institute for X-Optics, Hochschule Koblenz)
Mr
Johannes Overbuschmann
(Center of Advanced European Studies and Research)
Dr
Marek Wieland
(Institute for Experimental Physics, Universität Hamburg)
Prof.
Markus Drescher
(The Hamburg Centre for Ultrafast Imaging, Universität Hamburg)
Mr
Stefan Baumbach
(Institute for X-Optics, Hochschule Koblenz)
Mr
Thomas Nisius
(Institute for X-Optics, Hochschule Koblenz)
Prof.
Thomas Wilhein
(Institute for X-Optics, Hochschule Koblenz)
