Grenz- und Oberflächenphysik, Universität Hamburg

Dr. Robert Frömter

Wissenschaftlicher Mitarbeiter

Anschrift:	Universität Hamburg CHyN - Center for Hybrid Nanostructures Luruper Chaussee 149, Geb. 600 22761 Hamburg
Telefon:	+49 (40) 42838 -1643
Mail:	rfroemte@physik.uni-hamburg.de
Büro:	R3.15

Forschungsschwerpunkte

Vektorielle Untersuchung der Magnetisierungsstruktur von ultradünnen Filmen und Nanostrukturen im Rasterelektronenmikroskop mit Polarisationsanalyse (SEMPA).

Röntgenholographische Mikroskopie (XHM) von magnetischen Schichtsystemen und Nanostrukturen bei PETRA III und am FLASH.

Grundlagen der Focused Ion Beam (FIB) Strukturierung.

Publikationen

2021

A. Philippi-Kobs, L. Müller, M.H. Berntsen, W. Roseker, M. Riepp, K. Bagschik, J. Wagner, R. Frömter, M. Danailov, F. Capotondi, E. Pedersoli, M. Manfredda, M. Kiskinova, M. Stransky, V. Lipp, A. Scherz, B. Ziaja, H.P. Oepen, G. Grübel
Ultrafast Demagnetization Excited by Extreme Ultraviolet Light From a Free-Electron Laser
submitted, (2021).
C. Nweze, T.E. Glier, S. Scheitz, L. Westphal, F. Biebl, S. Buchenau, L.O. Akinsinde, N. Kohlmann, L. Kienle, I. Gonz�lez D�az-Placio, R. Frömter, R. Zierold, R. Blick, N. Huse, and M. Rübhausen
Quantum Confinement of the Spin-Berry Phase on 1D topological surfaces of single Bi₂Se₃ nanowires
submitted, (2021).
T. Anlauf, M. Prada, S. Freercks, B. Bosnjak, R. Frömter, J. Sichau, H.P. Oepen, L. Tiemann, and R.H. Blick
Polarization amplification by spin-doping in nanomagnetic/graphene hybrid systems
Phys. Rev. Materials 5, 034006, (2021).

2020

K. Bagschik, M. Schneider, J. Wagner, R. Buß, M. Riepp, A. Philippi-Kobs, L. Müller, W. Roseker, F. Trinter, M. Hoesch, J. Viefhaus, S. Eisebitt, G. Grübel, H.P. Oepen, and R. Frömter
Enabling time-resolved 2D spatial-coherence measurements using the Fourier-analysis method with an integrated curved-grating beam monitor
Opt. Lett. 45, 5591, (2020).
K. Bagschik, J. Wagner, R. Buß, M. Riepp, A. Philippi-Kobs, L. Müller, J. Buck, F. Trinter, F. Scholz, J. Seltmann, M. Hoesch, J. Viefhaus, G. Grübel, H.P. Oepen, and R. Frömter
Direct 2D spatial-coherence determination using the Fourier-analysis method: Multi-parameter characterization of the P04 beamline at PETRA III
Opt. Express 28, 7282, (2020).
M.J. Meijer, J. Lucassen, O. Kurnosikov, H.J.M. Swagten, B. Koopmans, R. Lavrijsen, F. Kloodt-Twesten, R. Frömter, and R.A. Duine
Magnetic chirality controlled by the interlayer exchange interaction
Phys. Rev. Lett. 124, 207203, (2020).

2019

M. Riepp, L. Müller, A. Philippi-Kobs, W. Roseker, R. Rysov, K. Bagschik, M. Walther, T. Golz N. Stojanovic, G. Grübel, R. Frömter, H.P. Oepen, D. Naumenko, E. Pedersoli, F. Capotondi, and M. Kiskinova
Ultrafast magnetization dynamics at the low-fluence limit supported by external magnetic fields
Proceedings of the 39th International Free-Electron Laser Conference, 574, (2019).
J. Lucassen, M.J. Meijer, O. Kurnosikov, H.J.M. Swagten, B. Koopmans, R. Lavrijsen, F. Kloodt-Twesten, R. Frömter, R.A. Duine
Tuning magnetic chirality by dipolar interactions
Phys. Rev. Lett. 123, 157201, (2019).
F. Kloodt-Twesten, S. Kuhrau, H.P. Oepen, and R. Frömter
Measuring the Dzyaloshinskii-Moriya interaction of the epitaxial Co/Ir(111) interface
Phys. Rev. B 100, 100402(R), (2019).

2018

R. Frömter, E.C. Corredor, S. Hankemeier, F. Kloodt-Twesten, S. Kuhrau, F. Lofink, S. Rößler, and H.P. Oepen
Imaging the Interaction of Electrical Currents with Magnetization Distributions
in "Atomic- and Nanoscale Magnetism" ed. R. Wiesendanger, pp 343-358, Springer, Cham, (2018).
S. Kuhrau, F. Kloodt-Twesten, Ch. Heyn, H.P. Oepen, and R. Frömter
Cap-layer-dependent oxidation of ultrathin cobalt films and its effect on the magnetic contrast in scanning electron microscopy with polarization analysis
Appl. Phys. Lett. 113, 172403, (2018).
L. Müller, G. Hartmann, S. Schleitzer, M.H. Berntsen, M. Walther, R. Rysov, W. Roseker, F. Scholz, J. Seltmann, L. Glaser, J. Viefhaus, K. Mertens, K. Bagschik, R. Frömter, A. De Fanis, I. Shevchuk, K. Medjanik, G. Öhrwall, H.P. Oepen, M. Martins, M. Meyer, and G. Grübel
Note: Soft X-ray Transmission Polarizer Based on Ferromagnetic Thin Films
Rev. Sci. Instrum. 89, 036103, (2018).
F. Kloodt-Twesten, S. Kuhrau, P. Staeck, D.R. Cavicchia, F. Lofink, H.P. Oepen, and R. Frömter
Coupling between vortices and antivortices in a cross-tie wall studied by time-resolved SEMPA
Phys. Rev. B 97, 024426, (2018).

2017

J. Lucassen, F. Kloodt-Twesten, R. Frömter, H.P. Oepen, R.A. Duine, H.J.M. Swagten, B. Koopmans, and R. Lavrijsen
Scanning electron microscopy with polarization analysis for multilayered chiral spin textures
Appl. Phys. Lett. 111, 132403, (2017).
E.C. Corredor, S. Kuhrau, F. Kloodt-Twesten, R. Frömter, and H.P. Oepen
SEMPA investigation of the Dzyaloshinskii-Moriya interaction in the single, ideally grown Co/Pt(111) interface
Phys. Rev. B 96, 060410(R), (2017).
F. Lofink, A. Philippi-Kobs, M.R. Rahbar Azad, S. Hankemeier, G. Hoffmann, R. Frömter, and H.P. Oepen
Domain walls in bent nanowires
Phys. Rev. Applied 8, 024008, (2017).
M. Seifert, L. Schultz, R. Schäfer, S. Hankemeier, R. Frömter, H.P. Oepen, and V. Neu
Micromagnetic investigation of domain and domain wall evolution through the spin-reorientation transition of an epitaxial NdCo₅ film
New J. Phys. 19, 033002, (2017).

2016

K. Bagschik, R. Frömter, J. Bach, B. Beyersdorff, L. Müller, S. Schleitzer, M.H. Berntsen, C. Weier, R. Adam, J. Viefhaus, C.M. Schneider, G. Grübel, and H.P. Oepen
Employing soft x-ray resonant magnetic scattering to study domain sizes and anisotropy in Co/Pd multilayers
Phys. Rev. B 94, 134413, (2016).
K. Bagschik, R. Frömter, L. Müller, W. Roseker, J. Bach, P. Staeck, C. Thönnißen, S. Schleitzer, M.H. Berntsen, C. Weier, R. Adam, J. Viefhaus, C.M. Schneider, G. Grübel, and H.P. Oepen
Spatial coherence determination from the Fourier analysis of a resonant soft X-ray magnetic speckle pattern
Opt. Express 24, 23162, (2016).
A. Gaul, S. Hankemeier, D. Holzinger, N.D. Müglich, P. Staeck, R. Frömter, H.P. Oepen, and A. Ehresmann
Engineered magnetic domain textures in exchange bias bilayer systems
J. Appl. Phys. 120, 033902, (2016).
F. Klein, U. Treske, A. Koitzsch, D.R. Cavicchia, C. Thönnißen, R. Frömter, T. Roch, and T. Mühl
Nanoscale scanning electron microscopy based graphitization in tetrahedral amorphous carbon thin films
Carbon 107, 536, (2016).
R. Frömter, F. Kloodt, S. Rößler, A. Frauen, P. Staeck, D.R. Cavicchia, L. Bocklage, V. Röbisch, E. Quandt, and H.P. Oepen
Time-resolved scanning electron microscopy with polarization analysis
Appl. Phys. Lett. 108, 142401, (2016).

2015

A. Casiraghi, T. Rincón Domínguez, S. Rößler, K.J.A. Franke, D. López González, S.J. Hämäläinen, R. Frömter, H.P. Oepen, and S. van Dijken
Influence of elastically pinned magnetic domain walls on magnetization reversal in multiferroic heterostructures
Phys. Rev. B 92, 054406, (2015).
C. Weier, R. Adam, D. Rudolf, R. Frömter, P. Grychtol, G. Winkler, A. Kobs, H.P. Oepen, H.C. Kapteyn, M.M. Murnane, and C.M. Schneider
Femtosecond-laser-induced modifications in Co/Pt multilayers studied with tabletop resonant magnetic scattering
Europhys. Lett. 109, 17001, (2015).

2014

E.C. Corredor, J.I. Arnaudas, M. Ciria, F. Lofink, S. Rößler, R. Frömter, and H.P. Oepen
Strain-induced spin reorientation of bcc-like iron films grown on Cu(001)
Phys. Rev. B 90, 184410, (2014).
D. Wilson, D. Rudolf, C. Weier, R. Adam, G. Winkler, R. Frömter, S. Danylyuk, K. Bergmann, D. Grützmacher, C.M. Schneider, and L. Juschkin
Generation of circularly polarized radiation from a compact plasma-based extreme ultraviolet light source for tabletop X-ray magnetic circular dichroism studies
Rev. Sci. Instrum. 85, 103110, (2014).
M.R. Rahbar Azad, A. Kobs, B. Beyersdorff, P. Staeck, G. Hoffmann, R. Frömter, and H.P. Oepen
Magnetostatic interaction of permalloy rectangles exhibiting a Landau state investigated by magnetotransport of single rectangles
Phys. Rev. B 90, 014404, (2014).
S. Rößler, S. Hankemeier, B. Krüger, F. Balhorn, R. Frömter, and H.P. Oepen
Nonadiabatic spin-transfer torque of magnetic vortex structures in a permalloy square
Phys. Rev. B 89, 174426, (2014).
P. Skopintsev, A. Singer, J. Bach, L. Müller, B. Beyersdorff, S. Schleitzer, O. Gorobtsov, A. Shabalin, R.P. Kurta, D. Dzhigaev, O.M. Yefanov, L. Glaser, A. Sakdinawat, Y. Liu, G. Grübel, R. Frömter, H.P. Oepen, J. Viefhaus, and I.A. Vartanyants
Characterization of spatial coherence of synchrotron radiation with non-redundant arrays of apertures
J. Synchrotron Rad. 21, 722, (2014).
H.H. Langner, A. Vogel, B. Beyersdorff, M. Weigand, R. Frömter, H.P. Oepen, and G. Meier
Local modification of the magnetic vortex-core velocity by gallium implantation
J. Appl. Phys. 115, 103909, (2014).

2013

L. Müller, S. Schleitzer, C. Gutt, B. Pfau, S. Schaffert, J. Geilhufe, C. von Korff Schmising, M. Schneider, C.M. Günther, F. Büttner, F. Capotondi, E. Pedersoli, S. Düsterer, H. Redlin, A. Al-Shemmary, R. Treusch, J. Bach, R. Frömter, B. Vodungbo, J. Gautier, P. Zeitoun, H. Popescu, V. Lopez-Flores, N. Beaulieu, F. Sirotti, N. Jaouen, G. Malinowski, B. Tudu, K. Li, J. Lüning, H.P. Oepen, M. Kiskinova, S. Eisebitt, and G. Grübel
Ultrafast Dynamics of Magnetic Domain Structures Probed by Coherent Free-Electron Laser Light
Synch. Rad. News 26, (6), 27, (2013).
L. Müller, C. Gutt, B. Pfau, S. Schaffert, J. Geilhufe, F. Büttner, J. Mohanty, S. Flewett, R. Treusch, S. Düsterer, H. Redlin, A. Al-Shemmary, M. Hille, A. Kobs, R. Frömter, H.P. Oepen, B. Ziaja, N. Medvedev, S.K. Son, R. Thiele, R. Santra, B. Vodungbo, J. Lüning, S. Eisebitt, and G. Grübel
Breakdown of the X-Ray Resonant Magnetic Scattering Signal during Intense Pulses of Extreme Ultraviolet Free-Electron-Laser Radiation
Phys. Rev. Lett. 110, 234801, (2013).
F. Capotondi, E. Pedersoli, N. Mahne, R.H. Menk, G. Passos, L. Raimondi, C. Svetina, G. Sandrin, M. Zangrando, M. Kiskinova, S. Bajt, M. Barthelmess, H. Fleckenstein, H.N. Chapman, J. Schulz, J. Bach, R. Frömter, S. Schleitzer, L. Müller, C. Gutt, and G. Grübel
Invited Article: Coherent imaging using seeded free-electron laser pulses with variable polarization: First results and research opportunities
Rev. Sci. Instrum. 84, 051301, (2013).
L. Müller, C. Gutt, S. Streit-Nierobisch, M. Walther, S. Schaffert, B. Pfau, J. Geilhufe, F. Büttner, S. Flewett, C.M. Günther, S. Eisebitt, A. Kobs, M. Hille, D. Stickler, R. Frömter, H.P. Oepen, J. Lüning, and G. Grübel
Endstation for ultrafast magnetic scattering experiments at the free-electron laser in Hamburg
Rev. Sci. Instrum. 84, 013906, (2013).
J. Jelli, K. M. Lebecki, S. Hankemeier, R. Frömter, H.P. Oepen, and U. Nowak
Magnetic domain structure in coupled rectangular nanostructures
IEEE Trans. Magn. 49, 1077, (2013).
M. Seifert, L. Schultz, R. Schäfer, V. Neu, S. Hankemeier, S. Rössler, R. Frömter, and H.P. Oepen
Domain evolution during the spin-reorientation transition in epitaxial NdCo₅ thin films
New J. Phys. 15, 013019, (2013).
M. Hille, A. Frauen, B. Beyersdorff, A. Kobs, S. Hesse, R. Frömter, and H.P. Oepen
Direct method for measuring the canting angle of magnetization
J. Appl. Phys. 113, 023902, (2013).

2012

B. Beyersdorff, S. Hankemeier, S. Rößler, Y. Stark, G. Hoffmann, R. Frömter, H.P. Oepen, and B. Krüger
Thermal effects in spin-torque assisted domain wall depinning
Phys. Rev. B 86, 184427, (2012).
B. Pfau, S. Schaffert, L. Müller, C. Gutt, A. Al-Shemmary, F. Büttner, R. Delaunay, S. Düsterer, S. Flewett, R. Frömter, J. Geilhufe, E. Guehrs, C.M. Günther, R. Hawaldar, M. Hille, N. Jaouen, A. Kobs, K. Li, J. Mohanty, H. Redlin, W.F. Schlotter, D. Stickler, R. Treusch, B. Vodungbo, M. Kläui, H.P. Oepen, J. Lüning, G. Grübel, and S. Eisebitt
Ultrafast optical demagnetization manipulates nanoscale spin structure in domain walls
Nat. Commun. 3, 1100, (2012).
K. Chen, R. Frömter, S. Rössler, N. Mikuszeit, and H.P. Oepen
Uniaxial Magnetic anisotropy of cobalt films deposited on sputtered MgO(001) substrates
Phys. Rev. B 86, 064432, (2012).
F. Lofink, S. Hankemeier, R. Frömter, J. Kirschner, and H.P. Oepen
Long-time stability of a low-energy electron diffraction spin polarization analyzer for magnetic imaging
Rev. Sci. Instrum. 83, 023708, (2012).

2011

L. V. Dzemiantsova, M. Karolak, F. Lofink, A. Kubetzka, B. Sachs, K. von Bergmann, S. Hankemeier, T. O. Wehling, R. Frömter, H. P. Oepen, A. I. Lichtenstein, and R. Wiesendanger
Multiscale magnetic study of Ni(111) and graphene on Ni(111)
Phys. Rev. B 84, 205431, (2011).
D. Stickler, R. Frömter, H. Stillrich, C. Menk, H.P. Oepen, C. Gutt, S. Streit-Nierobisch, L.-M. Stadler, G. Grübel, C. Tieg, and F. Yakhou-Harris
Domain size in systems with canted magnetization
Phys. Rev. B 84, 104412, (2011).
R. Frömter, S. Hankemeier, H.P. Oepen, and J. Kirschner
Optimizing a low-energy electron diffraction spin-polarization analyzer for imaging of magnetic surface structures
Rev. Sci. Instrum. 82, 033704, (2011).
Y. Zhou, D. Stickler, Y. Du, E. Ahmad, Z. Lu, R. Frömter, H.P. Oepen, D. Wilton, and G. Pan
Size Effect on Magnetic Switching and Interlayer Magnetostatic Coupling in Spin-Valve Nanorings Exchange-Biased by Synthetic Antiferromagnets
IEEE Trans. Magn. 47, 214, (2011).

2010

C. Tieg, R. Frömter, D. Stickler, S. Hankemeier, A. Kobs, S. Streit-Nierobisch, C. Gutt, G. Grübel, and H. P. Oepen
Imaging the in-plane magnetization in a Co microstructure by Fourier transform holography
Opt. Express 18, 27251, (2010).
S. Hankemeier, A. Kobs, R. Frömter and H.P. Oepen
Controlling the properties of vortex domain walls via magnetic seeding fields
Phys. Rev. B 82, 064414, (2010).
C. Tieg, R. Frömter, D. Stickler, H. Stillrich, C. Menk, S. Streit-Nierobisch, L.-M. Stadler, C. Gutt, O. Leupold, M. Sprung, G. Grübel, and H.P. Oepen
Overcoming the field-of-view restrictions in soft x-ray holographic imaging
J. Phys.: Conf. Ser. 211, 012024, (2010).
C. Gutt, S. Streit-Nierobisch, L.M. Stadler, B. Pfau, C.M. Günther, R. Könnecke, R. Frömter, A. Kobs, D. Stickler, H.P. Oepen, R.R. Fäustlin, R. Treusch, J. Feldhaus, E. Weckert, I.A. Vartanyants, M. Grunze, A. Rosenhahn, T. Wilhein, S. Eisebitt, and G. Grübel
Single-pulse resonant magnetic scattering using a soft x-ray free-electron laser
Phys. Rev. B 81, 100401(R), (2010).
H. Stillrich, C. Menk, R. Frömter, and H.P. Oepen
Magnetic anisotropy and spin reorientation in Co/Pt multilayers: influence of preparation
J. Magn. Magn. Mater. 322, 1353, (2010).
B. Krüger, M. Najafi, S. Bohlens, R. Frömter, D. P. F. Möller, and D. Pfannkuche
Proposal of a Robust Measurement Scheme for the Nonadiabatic Spin Torque Using the Displacement of Magnetic Vortices
Phys. Rev. Lett. 104, 077201, (2010).
D. Stickler, R. Frömter, H. Stillrich, C. Menk, C. Tieg, S. Streit-Nierobisch, M. Sprung, C. Gutt, L.-M. Stadler, O. Leupold, G. Grübel, and H.P. Oepen
Soft x-ray holographic microscopy
Appl. Phys. Lett. 96, 042501, (2010).

2009

S. Streit-Nierobisch, D. Stickler, C. Gutt, L.-M. Stadler, H. Stillrich, C. Menk, R. Frömter, C. Tieg, O. Leupold, H. P. Oepen, and G. Grübel
Magnetic soft x-ray holography study of focused ion beam-patterned Co/Pt multilayers
J. Appl. Phys. 106, 083909, (2009).
A. Kobs, H. Spahr, D. Stickler, S. Hankemeier, R. Frömter, and H.P. Oepen
Magnetic energies of single submicron permalloy rectangles determined via magnetotransport
Phys. Rev. B 80, 134415, (2009).
S Hankemeier, R Frömter, N. Mikuszeit, D. Stickler, H. Stillrich, S. Pütter, E.Y. Vedmedenko, H.P. Oepen
Magnetic Ground State of Single and Coupled Permalloy Rectangles
Phys. Rev. Lett. 103, 147204, (2009).
C. Gutt, L.-M. Stadler, S. Streit-Nierobisch, A.P. Mancuso, A. Schropp, B. Pfau, C.M. Gunther, R. Könnecke, J. Gulden, B. Reime, J. Feldhaus, E. Weckert, I.A. Vartanyants, O. Hellwig, F. Staier, R. Barth, M. Grunze, A. Rosenhahn, D. Stickler, H. Stillrich, R. Frömter, H.P. Oepen, M. Martins, T. Nisius, T. Wilhein, B. Faatz, N. Guerassimova, K. Honkavaara, V. Kocharyan, R. Treusch, E. Saldin, S. Schreiber, E.A. Schneidmiller, M.V. Yurkov, S. Eisebitt, and G. Grübel,
Resonant magnetic scattering with soft x-ray pulses from a free-electron laser operating at 1.59 nm
Phys. Rev. B 79, 212406, (2009).
H. Stillrich, C. Menk, R. Frömter, and H.P. Oepen
Magnetic anisotropy and the cone state in Co/Pt multilayer films
J. Appl. Phys. 105, 07C308, (2009).
Y. Stark, R. Frömter, D. Stickler, and H.P. Oepen
Sputter yields of single- and polycrystalline metals for application in focused ion beam technology
J. App. Phys. 105, 013542, (2009).
A. P. Mancuso, A. Schropp, B. Reime, L.-M. Stadler, A. Singer, J. Gulden, S. Streit-Nierobisch, C. Gutt, G. Grübel, J. Feldhaus, F. Staier, R. Barth, A. Rosenhahn, M. Grunze, T. Nisius, T. Wilhein, D. Stickler, H. Stillrich, R. Frömter, H. P. Oepen, M. Martins, B. Pfau, C. M. Günther, R. Könnecke, S. Eisebitt, B. Faatz, N. Guerassimova, K. Honkavaara, V. Kocharyan, R. Treusch, E. Saldin, S. Schreiber, E. A. Schneidmiller, M. V. Yurkov, E. Weckert, and I. A. Vartanyants
Coherent-Pulse 2D Crystallography Using a Free-Electron Laser X-Ray Source
Phys. Rev. Lett. 102, 035502, (2009).

2008

R. Frömter, H. Stillrich, C. Menk, HP. Oepen
Imaging the cone state of the spin reorientation transition.
Phys. Rev. Lett. 100, 207202, (2008).
S. Hankemeier, K. Sachse, Y. Stark, R. Frömter, HP. Oepen
Ultrahigh current densities in Permalloy nanowires on diamond
Appl. Phys. Lett. 92, 242503, (2008).
D. Stickler, R. Frömter, W. Li, A. Kobs, HP. Oepen
Integrated setup for the fabrication and measurement of magnetoresistive nanoconstrictions in ultrahigh vacuum.
Rev. Sci. Instrum. 79, 103901, (2008).

2007

H. P. Oepen and R. Frömter
Scanning Electron Microscopy with Polarization Analysis
in "The Handbook of Magnetism and Advanced Magnetic Materials", Volume 3, Wiley, Chichester, (2007).
S. Pütter, H. Stillrich, A. Frömsdorf, C. Menk, R. Frömter, S. Förster, HP. Oepen
Magnetic antidot arrays using SiO2 filled diblock copolymer micelles as ion etching mask
J. Magn. Magn. Mater. 316, E40-E43, (2007).
R. Frömter, C. Menk, H. Stillrich, HP. Oepen
Imaging the domain pattern of the canted magnetization state in Co/Pt multilayer films
Vacuum 82, 395-401, (2007).

2005

N. Mikuszeit, S. Pütter, R. Frömter, and H. P. Oepen
Magneto-optic Kerr effect: Incorporating the nonlinearities of the analyzer into static photometric ellipsometry analysis
J. App. Phys. 97, 103107, (2005).

2003

R. Frömter, H.P.Oepen & J. Kirschner
A miniaturized detector for high-resolution SEMPA
Appl. Phys. A. 76, 869, (2003).