Dr. Wolfgang-Dietrich Engel
wolfgang.engel(at)mbi-berlin.de
+49 30 6392 1337
B1: Electron and Spin Dynamics
Haus B, 2.12
Position
- Project Coordinator: 4.3 "Nanoscaled Samples and Integrated Optics",
- Member of Project: 3.3 "Transient Structures and lmaging with X-rays"
Research
The Laboratory for Nanoscale Samples and Optics supports several experiments in different scientific projects of the MBI. We develop and produce thin-film sample systems on various substrates or free-standing with the focus on magnetic multilayers, alloys and metal foils using magnetron sputtering and thermal evaporation.
The close integration of deposition, structuring and characterization of these systems with experiments promotes fast feedback on sample performance and rapid development cycles. We collaborate closely with several MBI projects as well as with external cooperation partners to provide custom sample-related services.
To enable new experimental techniques as for example Spin Hall Effect measurements and skyrmion nucleation via high current density, a UV-lithography system is used to create masks, which enables necessary structuring and lift-off processes.
Topographic and magnetic characterization is carried out via atomic and magnetic force microscopy (AFM/MFM), electron microscopy (SEM, EDX), X-ray reflectivity and diffraction, Kerr-magnetometry and Kerr-microscopy.
In close cooperation with the central facility for electron microscopy (ZELMI) at the TU Berlin the 3D patterning on a few-micrometer and nanometer scale via electron beam lithography (EBL) and focused ion beam milling (FIB) is carried out.
We recently expanded the applications in the laboratory and adapted them for internal users:
The MFM setup can now also be used for targeted preparation and imaging of magnetization states, as a variably adjustable magnetic field has been integrated in combination with an fs laser and a current pulse setup.
A 2D transfer microscope is now available to precisely position extremely thin flakes (<100nm) on a substrate.
As part of the ERDF project SpezFX, we are investigating the possibility of commercially producing filter systems for the soft x-ray range.
MBI Publikationen
- Deterministic generation and guided motion of magnetic skyrmions by focused He+-ion irradiation Nano Letters 22 (2022) 4028-4035
- All-optical switching on the nanometer scale excited and probed with femtosecond extreme ultraviolet pulses Nano Letters 22 (2022) 4453-4458
- Tailoring optical excitation to control magnetic skyrmion nucleation Physical Review B 106 (2022) 054435/1-10
- Lattice dynamics and ultrafast energy flow between electrons, spins, and phonons in a 3d ferromagnet Physical Review Research 3 (2021) 023032/1-14
- High-speed spatial encoding of modulated pump-probe signals with slow area detectors Measurement Science and Technology 32 (2021) 025901/1-7
- Application concepts for ultrafast laser-induced skyrmion creation and annihilation Applied Physics Letters 118 (2021) 192403/1-7
- The patterning toolbox FIB-o-mat: Exploiting the full potential of focused helium ions for nanofabrication Beilstein Journal of Nanotechnology 12 (2021) 304-318
- Wide-field magneto-optical microscope to access quantitative magnetization dynamics with femtosecond temporal and sub-micrometer spatial resolution Journal of Applied Physics 130 (2021) 083905/1-9
- Observation of fluctuation-mediated picosecond nucleation of a topological phase Nature Materials 20 (2021) 30–37
- Distinct spectral response in M-edge magnetic circular dichroism Physical Review B 102 (2020) 100405(R)/1-6