Dresden 2020 – scientific programme
The DPG Spring Meeting in Dresden had to be cancelled! Read more ...
Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 57: Skyrmions IV (joint session MA/TT)
TT 57.6: Talk
Thursday, March 19, 2020, 10:45–11:00, POT 6
Topologically Non-trivial Magnetic and Polar Patterns in Lacunar Spinels — •Markus Preißinger1, Hans-albrecht Krug von Nidda1, Axel Lubk2, Sándor Bordács3, Hiroshi Nakamura4, Vladimir Tsurkan1, and István Kézsmárki1 — 1Experimentalphysik V, Universität Augsburg — 2Advanced Methods of Electron Microscopy, IFW Dresden — 3Magneto-Optical Spectroscopy Group, Budapest University of Technology and Economics — 4Department of Materials Science and Engineering, Kyoto University
The lacunar spinels Ga(V/Mo)4(S/Se)8 have been the first candidates, where the emergence of Néel-type skyrmions, induced by Dzyaloshinsky-Moriya interaction, has been reported. This group of materials undergo a Jahn-Teller transition at about 40 K losing inversion symmetry in the process. Upon further cooling the system enters a magnetically ordered state. The ground state is a cycloidal phase, while critical fields strongly depend on the direction in which the magnetic field is applied [1][2]. In an attempt to image skyrmions with Lorentz-transmission-electron microscopy (LTEM), we succeeded to find the cycloidal ground state in thin lamellae of GaV4(S/Se)8 (<100nm) at a hugely increased temperature simultaneously to the Jahn-Teller distortion. In thin lamellae of GaMo4S8 no magnetic texture but a regular pattern of polarised structural domains has been found, presumably indicating polar skyrmions.
[1] I. Kézsmárki, NMAT 2015, Vol14, pp 1116-1122;
[2] S. Bordács Sci. Rep. 2017, Vol 7, Article number 7548