Abstract
Magnetic interfaces and the phenomena arising from them drive both the design of modern spintronics and fundamental research. Recently, it was revealed that through designing magnetic frustration in configurationally complex entropy stabilized oxides, exchange bias can occur in structurally single crystal films. This eliminates the need for complex heterostructures and nanocomposites in the design and control of magnetic response phenomena. In this work, we demonstrate through hole doping of a high entropy perovskite oxide that tuning of magnetic responses can be achieved. With detailed magnetometry, we show magnetic coupling exhibiting a variety of magnetic responses including exchange bias and antiferromagnetic spin reversal in the entropy stabilized ABO3 perovskite oxide La1-xSrx(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3 family. We find that manipulation of the A-site charge state can be used to balance magnetic phase compositions and coupling responses. This allows for the creation of highly tunable exchange bias responses. In the low Sr doping regime, a spin frustrated region arising at the antiferromagnetic phase boundary is shown to directly couple to the antiferromagnetic moments of the film and emerges as the dominant mechanism, leading to a vertical shift of magnetization loops in response to field biasing. At higher concentrations, direct coupling of antiferromagnetic and ferromagnetic regions is observed. This tunability of magnetic coupling is discussed within the context of these three competing magnetic phases, revealing critical features in designing exchange bias through exploiting spin frustration and disorder in high entropy oxides.
| Original language | English |
|---|---|
| Article number | 031118 |
| Journal | APL Materials |
| Volume | 11 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 1 2023 |
Funding
All aspects of this work were supported by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences (BES), Materials Sciences and Engineering Division. Dynamic magnetometry measurements were performed as a user project at the Center for Nanophase Materials Sciences, which is sponsored at Oak Ridge National Laboratory (ORNL) by the Scientific User Facilities Division, BES, DOE. The work at Los Alamos National Laboratory was supported by the NNSA’s Laboratory Directed Research and Development Program and was performed, in part, at the CINT, an Office of Science User Facility operated for the U.S. Department of Energy Office of Science through the Los Alamos National Laboratory. Los Alamos National Laboratory is operated by Triad National Security, LLC, for the National Nuclear Security Administration of U.S. Department of Energy (Contract No. 89233218CNA000001). Work at the National High Magnetic Field Laboratory was supported by NSF Cooperative Agreement No. DMR-1644779, the State of Florida, and the U.S. DOE. J.S. acknowledges support from the DOE Basic Energy Science Field Work Project Science in 100 T.
| Funders | Funder number |
|---|---|
| DOE Basic Energy Science Field Work Project Science in 100 T. | |
| State of Florida | |
| National Science Foundation | DMR-1644779 |
| U.S. Department of Energy | |
| Office of Science | |
| Basic Energy Sciences | |
| National Nuclear Security Administration | 89233218CNA000001 |
| Los Alamos National Laboratory | |
| Division of Materials Sciences and Engineering | |
| Center for Integrated Nanotechnologies |