Speaker
Description
Magnetic materials represent a key component in the industry. One of the most common and used magnetic material parameters is magneto-crystalline anisotropy, which takes place in permanent magnets, storage devices, etc. In addition, magnetoelastic behavior is widely used in many applications, such as acoustic actuators, transducers, or sensors, providing desirable fast response and high efficiency. The study of magnetic exchange interactions is substantial and engaging from the point of view of material design. Interlayer exchange coupling has been intensively investigated for over thirty years and is incorporated in almost all spintronic devices, e.g. into the hard data disk storages. However in past, research was focused on the coupling between magnetic layers across a nonmagnetic spacer layer. Here we find that antiferromagnetic interlayer exchange coupling can be achieved across spacer layers containing over sixty atomic percent of magnetic materials. X-ray magnetic circular dichroism measurements reveal that the magnetic atoms in the spacer layer have a large magnetic moment. Magnetic atoms in the spacer layer can double the coupling strength, leading to the largest antiferromagnetic bilinear coupling observed in magnetic multilayers deposited with the industrial technique of choice, magnetron sputtering. Electronic structure calculations predict a dependence of interlayer exchange coupling on both the magnetic material concentration and the spacer layer thickness. The DFT calculations also offer insight into the role of magnetic atom interactions within the spacer layer in influencing interlayer exchange coupling, the role of the interface as well as the role of various magnetic transitional metals in spacer[1-2].
Acknowledgement:
The authors acknowledge financial support from the Natural Sciences and Engineering Research Council of Canada (NSERC), the Czech Science Foundation, Project No. 22-35410K and the projects e-INFRA CZ (ID:90254)
and QM4ST No. CZ.02.01.01/00/22_008/0004572 by the Ministry of Education, Youth and Sports of the Czech Republic.
References:
[1] K. Winther, Z. R. Nunn, J. Lisik, S. Arapan, D. Legut, F. Schulz, E. Goering, T. Mckinnon, S. Myrtle, and E. Girt, Physical Review Applied 22, 024058 (2024).
[2] S. Arapan, J. Priessnitz, D. Legut, A. Kovacs, H. Oezelt, D. Boehm, M. Gusenbauer, and T. Schrefl, "Effect of interface on magnetic exchange coupling in Co/Ru/Co trilayer: from ab-initio simulations to micromagnetics", https://doi.org/10.48550/arXiv.2501.08724
[3] Z. R. Nunn, J. Lisik, P. Omelchenko, S. Koraltan, C. Abert, D. Suess, and E. Girt, J. of Applied Physics 133, 123901 (2023).
