Hydrogen Magneto-Ionics

Hydrogen magneto-ionics uses the electrochemical hydrogen loading of metals to control their magnetic properties. In our publication on hydrogen magneto-ionics in palladium/cobalt multilayers together with the Hellwig group, we have demonstrated that the hydrogen concentration in such multilayers directly influences their magnetic properties, most notably their coercivity. Furthermore, we have been able to show that the magnetic domain wall velocity is significantly reduced by hydrogen and have recorded the complete stopping of a propagating magnetic domain wall by hydrogen loading in a video. Our findings could provide new functionalities for magnetic data storage media that store information in the position of the domain wall. There is a press release from TU Chemnitz about our work (in German).

• M. Bischoff, R. Ehrler, F. Engelhardt, O. Hellwig, K. Leistner, M. Gößler, Magneto-Ionic Control of Coercivity and Domain-Wall Velocity in Co/Pd Multilayers by Electrochemical Hydrogen Loading, Advanced Functional Materials 34, 2405323 (2024), https://doi.org/10.1002/adfm.202405323

Magneto-Ionics on Spin Valves

In collaboration with the University of Kassel (AG Ehresmann), we have demonstrated a magneto-ionic effect in a spin valve structure. Such structures consist of two ferromagnetic layers separated by a non-magnetic spacer layer, where the magnetization of the lower of the two ferromagnetic layers is fixed by the exchange bias effect. The magneto-ionic effect in these structures is based on the electrochemical reduction/oxidation of a thin oxide layer, which forms on the upper ferromagnetic layer. However, magnetic interlayer coupling of both layers allows us to control the entire structure by magneto-ionics. Using this concept, we have not only achieved the reversible control of the exchange bias effect, but have also switched between single- and double-step hysteresis curves. This new device structure could allow the magneto-ionic control of more complex magnetic heterostructures through magnetic interlayer coupling and may be used for magnetic field sensors. 

• M. Gößler, J. Zehner, R. Huhnstock, F. Röder, R. Ehrler, O. Hellwig, A. Ehresmann, K. Leistner, Reversible magneto-ionic control of exchange bias in spin-valve-like heterostructures, ACS Applied Materials & Inferfaces, 17, 49671–49682 (2025), https://doi.org/10.1021/acsami.5c10187

Kontakt:

Dr. Markus Gößler

Tel.:       +49 (0) 371 531 37533
E-Mail:  markus.goessler@…
Raum:   1/150