an array of rolled up nanomembranes


Magnetic Microscopy and Thin Film Devices

In the group of Volker Neu we are interested in resolving the details of magnetic microstructures and complex magnetic textures on the nanoscale, mainly by advanced quantitative magnetic force microscopy techniques.

A current focus lies on field or current driven domain wall motion in possible memory or sensor devices and on exploring self-assembled roll-up technology for tailoring anisotropies and domain configurations.

Group Leader

Dr. Volker Neu

Office: B EG.06
Phone: +49 351 4659 237
E-mail

Topics & Highlights

The functionality of a ferroic device is intimately coupled to the configuration of domains, domain boundaries and the possibility for tailoring them. We developed a novel approach which allows the creation of new, metastable magnetic multidomain patterns with tailored wall configurations through a self-assembled geometrical transformation. By preparing a magnetic layer system on a polymeric platform including swelling layer, a repeated self-assembled rolling into a multiwinding tubular structure and un-rolling of the functional membrane is obtained. When polarizing the rolled-up 3D structure in a simple homogeneous magnetic field, the imprinted configuration translates into a regularly arranged multidomain configuration once the tubular structure is un-wound. The process is linked to the employed magnetic anisotropy with respect to the surface normal, and the geometrical transformation connects the angular with the lateral degrees of freedom. This combination offers unparalleled possibilities for designing new magnetic or other ferroic micropatterns.

V. Neu, I. Soldatov, R. Schäfer, D.D. Karnaushenko, A. Mirhajivarzaneh, D. Karnaushenko, O.G. Schmidt
Creating ferroic micropatterns through geometrical transformation
Nano Letters 21, 9889 (2021).

Magnetic force microscopy (MFM) has established its place as an extremely valuable method for the investigation of magnetic microstructures on the nanometer scale. Beyond being a purely qualitative imaging technique, quantitative MFM (qMFM) offers access to 3-dimensional magnetic textures on the nanometer scale in the surface-near region of arbitrary samples, when the imaging properties of the tip are quantitatively characterized. The Magnetic Microscopy and Thin Film Device group at IFW has long year experience, working on all relevant aspects of qMFM: tip calibration routines, dedicated calibration samples, probe development, and application to the study of various magnetic microtextures.

The latest development directly quantifies the 2D tip stray field function via single nitrogen vacancy (NV) magnetometry. This constitutes the first quantum calibrated measurement of an MFM probe’s TTF and hence opens the path to quantum traceable nanoscale stray magnetic field measurements.

 

H. Corte-León, V. Neu, A. Manzin, C. Barton, Y. Tang, M. Gerken, P. Klapetek, H.-W. Schumacher and O. Kazakova
Comparison and validation of different magnetic force microscopy calibration schemes
Small 16, 1906144 (2020).

B. Sakar, Y. Liu, S. Sievers, V. Neu, J. Lang, C. Osterkamp, M.L. Markham, O. Öztürk, F. Jelezko, H.-W. Schumacher
Quantum calibrated magnetic force microscopy
Phys. Rev. B 104, 214427 (2021).

last updated: 2022/01/18 hs