Contact

Group Members

  • Sabine Neitsch
  • Kenny Duschek
  • Liu Yang
  • Jonas Zehner

Former Group Members

  • Juliane Wunderwald
  • Norman Lange
  • Luwig Reichel
  • Christian Kozalla

Electric Field Control of Magnetism

Electric control of magnetism is a vision which drives intense research on magnetic semiconductors and multiferroics. Recently, also ultrathin metallic films were reported to show magnetoelectric effects at room temperature.

Our group works on electric field induced changes of magnetism in ultrathin FePt (CoPt) and composite FePt/Fe-O (CoPt/Co-O) films. The electric field is applied by an electrolyte. This allows to take advantage of double layer charging, ad-and desorption reactions, and electrochemical reactions to control the magnetism at the surface. 

The magnetic properties of our ultrathin (ca. 2 nm) films are measured by the anomalous Hall effect, which is very surface sensitive. We designed and constructed a unique in-situ electrochemical Hall cell that allows to measure changes in magnetism during charging in an electrolyte.

We achieved strong effects on saturation magnetization, coercivity, and anisotropy by exploiting reversible reduction/oxidation reactions. For an FePt/iron oxide composite film a field induced switching between an exchange coupled state and a non-exchange coupled state was achieved. The principle can be transferred to various metal/oxide combinations and represents a novel approach towards multifunctionality.

Our work also includes the investigation of magnetism at the first stages of electrodeposition of magnetic elements and alloys.

This work is funded by the DFG by the Eigene Stelle "Kontrolle der magnetischen Eigenschaften ultradünner metallischer Schichten durch ein elektrisches Feld in einem Elektrolyten" (LE2558/1-1).

We are always open for collaborations and we offer student jobs. Please do not hesitate to contact me!

 

 

Publications

Journal papers

2016

K. Duschek, D. Pohl, S. Faehler, K. Nielsch, K. Leistner: Research Update: Magnetoionic control of magnetization and anisotropy in layered oxide/metal heterostructures, APL Materials 4 (2016) Nr. 3, S. 32301/1-10 URL

2013

K. Leistner, N. Lange, S. Oswald, L. Schultz: (Invited) Reversible Change of Magnetism in FePt Films by Electrochemical Charging in a LiClO4 Based Electrolyte, ECS Transactions 50 (2013) Nr. 10, S. 49-56 URL

K. Leistner, J. Wunderwald, N. Lange, S. Oswald, M. Richter, H. Zhang, L. Schultz, S. Faehler: Electric-field control of magnetism by reversible surface reduction and oxidation reactions, Physical Review B 87 (2013) Nr. 22, S. 224411/1-7 URL

L. Reichel, S. Faehler, L. Schultz, K. Leistner: Initial preorder as condition for L10 ordering in ultrathin CoPt films, Journal of Applied Physics 114 (2013) Nr. 9, S. 93909/1-6 URL

L. Reichel, S. Oswald, S. Faehler, L. Schultz, K. Leistner: Electrochemically driven variation of magnetic properties in ultrathin CoPt films, Journal of Applied Physics 113 (2013), S. 143904/1-7 URL

2012

K. Leistner, N. Lange, J. Haenisch, S. Oswald, F. Scheiba, S. Faehler, H. Schloerb, L. Schultz: Electrode processes and in situ magnetic measurements of FePt films in a LiPF6 based electrolyte, Electrochimica Acta 81 (2012), S. 330-337 URL

2010

F. Kurth, M. Weisheit, K. Leistner, T. Gemming, B. Holzapfel, L. Schultz, S. Faehler: Finite-size effects in highly ordered ultrathin FePt films, Physical Review B 82 (2010) Nr. 18, S. 184404/1-8 URL

2008

K. Leistner, P. Schaaf, A. Voss, S. Faehler, L. Schultz, H. Schloerb: Interfacial Fe(III)-hydroxide formation during Fe–Pt alloy deposition, Electrochimica Acta 53 (2008) Nr. 23, S. 6973-6977 URL

K. Leistner, H. Schloerb, J. Thomas, L. Schultz, S. Faehler: Remanence enhancement in nanoscaled electrodeposited FePt films, Applied Physics Letters 92 (2008) Nr. 5, S. 52502/1-3 URL

2007

K. Zuzek Rozman, A. Krause, K. Leistner, S. Faehler, L. Schultz, H. Schloerb: Electrodeposition and hard magnetic properties of Co–Pt films in comparison to Fe–Pt films, Journal of Magnetism and Magnetic Materials 314 (2007) Nr. 2, S. 116-121 URL

2006

J. Buschbeck, S. Faehler, M. Weisheit, K. Leistner, J. McCord, B. Rellinghaus, L. Schultz: Thermodynamics and kinetics during pulsed laser annealing and patterning of FePt films, Journal of Applied Physics 100 (2006) Nr. 12, S. 123901/1-7 URL

A. Kumar, S. Faehler, H. Schloerb, K. Leistner, L. Schultz: Competition between shape anisotropy and magnetoelastic anisotropy in Ni nanowires electrodeposited within alumina templates, Physical Review B 73 (2006) Nr. 6, S. 64421/1-5 URL

K. Leistner, S. Faehler, H. Schloerb, L. Schultz: Preparation and characterization of electrodeposited Fe/Pt multilayers, Electrochemistry Communications 8 (2006) Nr. 6, S. 916-920 URL

K. Leistner, A. Krause, S. Faehler, H. Schloerb, L. Schultz: Electrode processes during Fe–Pt electrodeposition studied by electrochemical quartz crystal microbalance, Electrochimica Acta 52 (2006) Nr. 1, S. 170-176 URL

K. Leistner, S. Oswald, J. Thomas, S. Faehler, H. Schloerb, L. Schultz: Potential dependence of composition and structure of electrodeposited Fe–Pt films, Electrochimica Acta 52 (2006) Nr. 1, S. 194-199 URL

2005

K. Leistner, J. Thomas, S. Baunack, H. Schloerb, L. Schultz, S. Faehler: Influence of oxygen and copper in electrodeposited FePt films, Journal of Magnetism and Magnetic Materials 290-291 (2005) Nr. Part 2, S. 1270-1273 URL

2004

K. Leistner, J. Thomas, H. Schloerb, M. Weisheit, L. Schultz, S. Faehler: Highly coercive electrodeposited FePt films by postannealing in hydrogen, Applied Physics Letters 85 (2004) Nr. 16, S. 3498-3500 URL

K. Leistner, E. Backen, B. Schuepp, M. Weisheit, L. Schultz, H. Schloerb, S. Faehler: Phase formation, microstructure and hard magnetic properties of electrodeposited FePt films, Journal of Applied Physics 95 (2004) Nr. 11/Part 2, S. 7267-7269 URL