Dr. Wolfgang-Dietrich Engel
wolfgang.engel(at)mbi-berlin.de
+49 30 6392 1337
B1: Electron and Spin Dynamics
Building 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 Publications
- Coherent control of magnetization precession by doublepulse activation of effective fields from magnetoacoustics and demagnetization Applied Physics Letters 24 (2024) 102402/1-7
- Ultrafast opto-magnetic effects in the extreme ultraviolet spectral range Communications Physics 7 (2024) 191/1-8
- Coherent x-ray magnetic imaging with 5 nm resolution Optica 11 (2024) 234-237
- X-ray magnetic circular dichroism spectroscopy at the Fe L-edges with a picosecond laser-driven plasma source Optica 10 (2023) 450-455
- Pump-probe x-ray microscopy of photo-induced magnetization dynamics at MHz repetition rates Structural Dynamics 10 (2023) 024301/1-9
- Broadband spintronic terahertz source with peak electric fields exceeding 1.5 MV/cm Physical Review Applied 19 (2023) 034018/1-12
- Transient terahertz stark effect: a dynamic probe of electric interactions in polar liquids Journal of Physical Chemistry Letters 14 (2023) 5505–5510
- Ultrafast element- and depth-resolved magnetization dynamics probed by transverse magneto-optical Kerr effect spectroscopy in the soft x-ray range Physical Review Research 4 (2022) L022062/1-7
- Accelerating double pulse all-optical write/erase cycles in metallic ferrimagnets Applied Physics Letters 120 (2022) 112406/1-7
- Intrinsic energy flow in laser-excited 3d ferromagnets Physical Review Research 4 (2022) 013104 /1-13