Interface magnetism

Contact

Dr. Kay Potzger
Project group leader
Tel.: 0351-260-3244, 2411
E-Mail: k.potzger@hzdr.de


Group members

Dr. Rantej Bali

Alexander Schmeink


Former group members

Jonathan Ehrler
Dr. Maciej Oskar Liedke
Dr. Anna Semisalova
Naren Srinivasan

Alireza Heidarian
Julius Beck
Alevtina Smekhova

Oguz Yildirim
Steffen Cornelius
Camilo Otalora

Daniel Blaschke
Maik Butterling
Nico Spahn
Falk Meutzner
Armin Haase

Tim Andrae
Kerstin Bernert
Nikolas Blum
Marcel Höwler

Tina Nestler
Julia Osten
Artem Shalimov
Georg Talut
Gufei Zhang
Shengqiang Zhou


Meetings

-FWIN-G -meeting thursdays at 12:45 (Meeting minutes)


Downloads

PREM (Preisach simulations)

MBE sample sheet

Further MBE instructions: O:\Labs\MBE_712_108_108a


Lectures

- Magnetic materials, TUBA Freiberg, summer semester

Interface magnetism (FWIN-G)

Our group is investigating magnetic effects at interfaces between different structures. Those structures are created by means of thin film deposition and ion irradiation. One example are metallic multilayers where the magnetic properties are locally taylored by ion irradiation or the magnetic doping of non-magnetic materials. The interface-magnetism-group is working in different projects which are partially funded by external sources (see below).

FWING_2015

Own projects

Finished projects

  • MACHO (Magnetic anisotropies in Cobalt heterostructures induced by oxidation - with IFJ Cracow)
  • MEMRIOX (Memristive oxides - HGF Virtual Institute VH-VI-422)
  • DETI.2 (Defects in magnetic TiO2 - HRJRG-314)
  • Spin tranfer torque effects in metallic multilayers and tunnel structures (BMBF, FKZ 13N10144)
  • Embedded magnetic nanoparticles (DFG, PO1275/2-1)
  • Magnetic clusters in semiconductors
  • Magnetic multilayers

Positions

Are you interested in taking part in our scientific work, e.g. as a students lab assistant of for a Bachelor/Master thesis? Please also contact k.potzger@hzdr.de directly.

Or maybe you are generally interested in


Recent publications:

  • Laser-Rewriteable Ferromagnetism at Thin-Film Surfaces
    Ehrler, Jonathan; He, Miao; Shugaev, Maxim V.; Polushkin, Nikolay I.; Wintz, Sebastian; Liersch, Vico; Cornelius, Steffen; Hubner, Rene; Potzger, Kay; Lindner, Juergen; Fassbender, Juergen; Unal, Ahmet A.; Valencia, Sergio; Kronast, Florian; Zhigilei, Leonid V.; Bali, Rantej
    ACS APPLIED MATERIALS & INTERFACES  Volume: 10  Issue: 17  Pages: 15232-15239   2018  
    Abstract:
    Manipulation of magnetism using laser light is considered as a key to the advancement of data storage technologies. Until now, most approaches seek to optically switch the direction of magnetization rather than to reversibly manipulate the ferromagnetism itself. Here, we use, similar to 100 fs laser pulses to reversibly switch ferromagnetic ordering on and off by exploiting a chemical order disorder phase transition in Fe60Al40, from the B2 to the A2 structure and vice versa. A single laser pulse above a threshold fluence causes nonferromagnetic B2 Fe60Al40 to disorder and form the ferromagnetic A2 structure. Subsequent laser pulsing below the threshold reverses the surface to B2 Fe60Al40, erasing the laser-induced ferromagnetism. Simulations reveal that the order disorder transition is regulated by the extent of surface supercooling; above the threshold for complete melting throughout the film thickness, the liquid phase can be deeply undercooled before solidification. As a result, the vacancy diffusion in the resolidified region is limited and the region is trapped in the metastable chemically disordered state. Laser pulsing below the threshold forms a limited supercooled surface region that solidifies at sufficiently high temperatures, enabling diffusion-assisted reordering. This demonstrates that ultrafast lasers can achieve subtle atomic rearrangements in bimetallic alloys in a reversible and nonvolatile fashion.

Update 18.11.2018