Subgroup Lindfors-Vrejoiu: Complex oxide heterostructures
Complex oxide heterostructures sit at the intersection of Condensed Matter Physics, Materials Science, and Nanotechnology. When you stack different oxide materials layer by layer (often just a few atoms thick), you can create entirely new properties that don’t exist in the individual materials. We study oxide epitaxial heterostructures of ferromagnetic and ferroelectric layers interfaced with large spin orbit-coupling materials, and with nonmagnetic layers that exhibit metal-insulator transitions. Thus they are a rich playground for obtaining control over the effective magnetic anisotropy and over the formation of topologically nontrivial magnetic and polar textures. We use pulsed-laser deposition assisted by in situ reflective high-energy electron diffraction for growing heterostructures with monolayer accuracy.
Group members
Dr. Ionela Lindfors-Vrejoiu, Senior Researcher (https://orcid.org/0000-0003-3196-7313)
Tom Zander, PhD student (since July 2025)
Tobias Truschies, M.Sc. student (since October 2025)
Pulsed-laser deposition
Pulsed-laser deposition (PLD), equipped with reflective high-energy electron diffraction (RHEED) system (installed in July 2019, purchase from SURFACE systems+ technology GmbH).
Current research projects
- Novel types of magnetic order generated across epitaxial interfaces of 4d and 5d transition metal perovskite oxides (German Research Foundation DFG LI3015/3-1, No. 335038432)
- All-oxide epitaxial heterostructures for the generation and electric field control of topological spin textures (German Research Foundation DFG LI3015/5-1, No. 403504808)
Research results
1. SrZrO3/SrRuO3/SrIrO3 superlattices fabricated by PLD: microstructure investigations by scanning transmission electron microscopy (a), (d) and (f), SAED ((b) and (c)) and energy dispersive x-ray spectroscopy EDXS (e) (collaboration with Dr. Lei Jin and Dr. András Kovács, Ernst Ruska Centre Jülich).
2. Anomalous Hall effect resistance loops for asummetric SrZrO3/SrRuO3/SrIrO3 and SrZrO3/SrRuO3/SrHfO3 superlattices.
3. Cross section HAADF-STEM image of a PZT/SrTiO3 superlattice and the analysis of the atomic displacements revealing the formation of polar vortices and dipolar waves in the ferroelectric PZT layers (collaboration with Dr. Lei Jin, Ernst Ruska Centre, FZ Jülich).
4. Magnetic skyrmion bubbles in (La,Sr)(Mn,Ru)O3 multilayres investigated by magnetic force microscopy (collboration with Dr. Peter Milde, TU Dresden) and Lorentz TEM (collboration with Dr. Daniel Wolf and Prof. Axel Lubk, IFW Dresden).
5. Magnetization reversal via domain formation in a 5-unit-cell thick SrRuO3 film at 55 K, investigated by magnetic force microscopy (collboration with Dr. Peter Milde, TU Dresden).
Selected publications (since 2020)
Tuning the interlayer coupling in La0.7 Sr0.3 Mn 0.95 Ru 0.05 O 3/LaNiO3 multilayers with perpendicular magnetic anisotropy
J. Schöpf, V. Piva, P.H.M. van Loosdrecht,.., I. Lindfors-Vrejoiu,Physical Review Materials 8, 094410 (2024)
Disentangling the magneto-optic Kerr effect of manganite epitaxial heterostructures
J. Schöpf, P.H.M. van Loosdrecht, I Lindfors-Vrejoiu, AIP Advances 13, 035319 (2023)
Néel skyrmion bubbles in La0.7Sr0.3Mn1-xRuxO3 multilayers
J. Schöpf, A. Thampi, P. Milde, D. Ivaneyko, S. Kondovych, D. Kononenko, L. Eng, L. Jin, L. Yang, L. Wysocki,
P. H. M. van Loosdrecht, K. Richter, K. Yershov, D. Wolf, A. Lubk, I. Lindfors-Vrejoiu, Nano Letters 23, 3532 (2023)
Thickness and temperature dependence of the atomic-scale structure of SrRuO3 thin films
X. Zhang, A.N. Penn, L. Wysocki, Z. Zhang, P.H.M. van Loosdrecht, ..., I. Lindfors-Vrejoiu, D. Kumah, APL Materials 10 (5), 051107 (2022)
Magnetic interlayer coupling between ferromagnetic SrRuO3 layers through a SrIrO3 spacer
L. Wysocki, SE Ilse, L Yang, E Goering, F Gunkel, R Dittmann, P. H. M van Loosdrecht, I. Lindfors-Vrejoiu, Journal of Applied Physics 131 (13), 133902 (2022)
Enhancing the ferromagnetic interlayer coupling between epitaxial layers
L. Yang, L Jin, L Wysocki, J Schöpf, D Jansen, B Das, L Kornblum, P. H.M. van Loosdrecht, I .Lindfors-Vrejoiu, Physical Review B 104 (6), 064444 (2021)
Origin of the hump anomalies in the Hall resistance loops of ultrathin multilayers
L. Yang, L Wysocki, J Schöpf, L Jin, A Kovács, F Gunkel, R Dittmann, P. van Loosdrecht, I . Lindfors-Vrejoiu, Physical Review Materials 5 (1), 014403 (2021)
Validity of magnetotransport detection of skyrmions in epitaxial heterostructures
L. Wysocki, L Yang, F Gunkel, R Dittmann, PHM van Loosdrecht, I. Lindfors-Vrejoiu, Physical Review Materials 4 (5), 054402 (2020)
L. Wysocki, J Schöpf, M Ziese, L Yang, A Kovács, L Jin, R. B. Versteeg, …, I. Lindfors-Vrejoiu, ACS Omega 5 (11), 5824-5833 (2020)
G. Malsch, D Ivaneyko, P Milde, L Wysocki, L Yang, PHM van Loosdrecht, I. Lindfors-Vrejoiu, L. Eng, ACS Applied Nano Materials 3 (2), 1182-1190 (2020)
PhD and Master theses
Jörg Schöpf, PhD thesis: Manganite Based Magnetic Multilayers With Tunable Magnetic Textures And Interlayer Coupling, March 2026
Valentina Piva, Master thesis: Pulsed-laser deposition of ferroic oxide heterostructures for generating topologically non-trivial phases, July 2024
Lin Yang, PhD thesis: Ferromagnetic oxide multilayers investigated by magneto-optic Kerr effect and anomalous Hall effect, October 2022
Lena Wysocki, PhD thesis: Tunable magnetic anisotropy and magnetotransport properties of epitaxial oxide ferromagnetic heterostructures, June 2022
Jörg Schöpf, Master thesis: Design of a setup for simultaneous magneto-transport and magneto-optical effects of ferromagnetic thin film heterostructures, November 2019
Ramil Mirzighaaev, Master thesis: Magneto-optical studies of SrRuO3 thin film heterostructures, September 2018
Lena Wysocki, Master thesis: Magnetic Order in SrRuO3/SrIrO3/SrZrO3 Multilayers, April 2018
Bachelor theses
Lukas Schnecking: Influence of the interlayer exchange coupling on the magnetization reversal in ferromagnetic La0.7Sr0.3Mn0.9Ru0.1O3 multilayers, October 2025
Peter Lachmann: Ferroelectric superlattices grown by pulsed laser deposition for the study of topological polar structures, October 2025
Christine Konrath: Effects of ultrathin SrIrO3 top layer on the magnetic and magneto-transport properties of La0.7Sr0.3Mn0.9Ru0.1O3 epitaxial layers, November 2022
Daniel Jansen: Magneto-optical and Magneto-transport Investigations of Ru Substituted La0.7Sr0.3MnO3 Epitaxial Films, September 2020
Lena Bussmann: Raman Scattering Spectroscopy of Orbital Order in Epitaxial Vanadate Films, June 2016