Abstract
The collective rotations of oxygen octahedra play an important role in determining the physical properties of functional perovskite oxides. The epitaxial strain can serve as an effective means to modify the oxygen octahedral symmetry (OOS), i.e., oxygen octahedral rotation or tilt (OOR/OOT). However, the strain-OOS coupling that may alter the details of the OOS, thereby the physical properties, has not been fully understood. In this work, it is demonstrated that epitaxial strain can not only induce a structural phase transition but also precisely tune the degree of OOR. The correlated metal CaNbO3, which is orthorhombic, is studied by growing as epitaxial thin films. By imposing epitaxial strain, it is found that the film undergoes a structural phase transition from orthorhombic to tetragonal upon fully straining (i.e., from a+b−b− to a0a0c−). In unstrained films, the octahedral rotation along the c-axis is as large as 15.7° that can be tuned to 6.6° by strain. This finding offers a general approach to manipulating OOR/OOT via strain engineering in complex oxide heterostructures.
Original language | English |
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Journal | Advanced Materials Interfaces |
DOIs | |
State | Accepted/In press - 2024 |
Funding
This work was sponsored by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division, and in part by the National Quantum Information Science Research Centers, Quantum Science Center for theoretical calculations. S.W.H. and S.Y. acknowledge the support by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. NRF\u20102022R1F1A1072330) for the microscopy work. This research used resources of the Advanced Photon Source, a U.S. DOE Office of Science User Facility, operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE\u2010AC02\u201006CH11357, and the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE\u2010AC05\u201000OR22725 and resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE\u2010AC02\u201005CH11231 using NERSC award BES\u2010ERCAP0028956.
Keywords
- complex oxides
- epitaxy
- oxygen octahedral symmetry
- perovskites
- strain engineering