Abstract
Perovskite nickelates possess an intimate connection among the structural, electronic, and magnetic orders. We investigate how crystal-field disorder induced by cation size variance impacts the emergence of macroscopic magnetic, structural, and electronic behaviors in single crystal high-entropy oxide nickelate films. The degree of variation in cation sizes hosted on the lattice is found to strongly influence critical ordering temperatures. Resonant x-ray scattering and density functional theory describe how high-variance systems produce local lattice distortions that can be used to manipulate charge disproportionation. The disorder induced shifts to local structure are shown to function as a critical order parameter capable of decoupling the nickelates' distinctive magnetic ground state and metal-insulator transition from its charge ordered state, making it possible to stabilize room-temperature ordered phases not observed in low-variance ternary compounds.
| Original language | English |
|---|---|
| Article number | 013008 |
| Journal | Physical Review Research |
| Volume | 5 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 2023 |
Funding
Experiment design, sample synthesis, structural and chemical characterization, and computational modeling were supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), Materials Sciences and Engineering Division (MSED). This research used the Soft Inelastic X-ray Scattering (2-ID) and the Coherent Soft X-ray Scattering (23-ID-1) beamlines of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility, operated for the DOE Office of Science by Brookhaven National Laboratory Contract No. DE-SC0012704. 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). We also acknowledge resources made available through BNL/LDRD#19-013.