Abstract
Magnetic skyrmions have captivated physicists due to their topological nature and novel physical properties. In addition, skyrmions hold significant promise for future information technologies. A key barrier to realizing skyrmion-based devices has been stabilizing these spin structures under ambient conditions. In this paper, we demonstrate that the tunable magnetic properties of amorphous Fe/Gd mulitlayers enable the formation of skyrmion lattices which are stable over a large temperature and magnetic field parameter space, including room temperature and zero magnetic field. These skyrmions, having a hybrid nature displaying both Bloch-type and Néel-type characteristics, are stabilized by dipolar interactions rather than Dzyaloshinskii-Moriya interactions, typically considered a requirement for the generation of skyrmions. Small angle neutron scattering (SANS) was used in combination with soft x-ray microscopy to provide a unique, multiscale probe of the local and long-range order of these structures. The hexagonal lattice seen in SANS results from the hybrid skyrmion picture obtained with micromagnetic simulations. These results identify a pathway to engineer controllable skyrmion phases in thin film geometries which are stable at ambient conditions.
| Original language | English |
|---|---|
| Article number | 104406 |
| Journal | Physical Review Materials |
| Volume | 3 |
| Issue number | 10 |
| DOIs | |
| State | Published - Oct 10 2019 |
| Externally published | Yes |
Funding
The authors wish to acknowledge the contributions from John Smith (ORNL), Thomas Farmer (ISIS), and Ken Littrell (ORNL). Work at UCSD was supported by the research programs of the U.S. Department of Energy (DOE), Office of Basic Energy Sciences (Award No. DE-SC0003678). Work at the Advanced Light Source, Lawrence Berkeley National Lab (LBNL) was supported by the Director, Office of Science, BES, of the DOE (Contract No. DE-AC02-05CH11231). Mi-Young Im acknowledges support by the National Research Foundation (NRF) of Korea funded by the Ministry of Education, Science and ICT (2018K1A4A3A03075584, 2016M3D1A1027831, 2017R1A4A1015323) and by the DGIST R&D program of the Ministry of Science, ICT and future Planning (18-BT-02). Access to VSANS was provided by the Center for High Resolution Neutron Scattering, a partnership between the National Institute of Standards and Technology and the National Science Foundation under Agreement No. DMR-1508249. These results use the resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. This paper was authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this paper, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan .
| Funders | Funder number |
|---|---|
| National Science Foundation | DMR-1508249, DE-AC05-00OR22725, 1508249 |
| U.S. Department of Energy | |
| National Institute of Standards and Technology | |
| Office of Science | |
| Basic Energy Sciences | DE-AC02-05CH11231, DE-SC0003678 |
| Ministry of Science, ICT and Future Planning | 18-BT-02 |
| National Research Foundation of Korea | |
| Ministry of Education and Science | 2017R1A4A1015323, 2018K1A4A3A03075584, 2016M3D1A1027831 |
| Daegu Gyeongbuk Institute of Science and Technology |