Identifying the Limits of Strain Engineering in NaNbO<sub>3</sub> Ultrathin Films
Epitaxial NaNbO<sub>3</sub> ultrathin films are grown on single-crystal substrates with a wide range of compressive (-6.24%) and tensile (+7.13%) strain. High-resolution X-ray diffraction reveals a coherently strained state of NaNbO<sub>3</sub> thin films within the strain range from -1.42 to 1.86%, beyond which the films are in relaxed states. This is accompanied by a change in the growth mode from step-flow growth in strained films to coalesced island growth in relaxed films. Piezoresponse force microscopy measurements, including domain writing and reading, reveal a single vertical ferroelectric domain for the compressive films, while the tensile films exhibit a mixture of multiple vertical domains. The first-principles calculations confirm the stability of strained NaNbO<sub>3</sub>. Our results provide important information for the understanding and engineering of strained functional thin films.
Authors
- Qibin Zeng (ORCID: https://orcid.org/0000-0001-9307-0830)
- Wenting Zhao (ORCID: https://orcid.org/0000-0002-6143-5185)
- Jiangbo Luo (ORCID: https://orcid.org/0000-0002-6859-4285)
- Seeram Ramakrishna (ORCID: https://orcid.org/0000-0001-8479-8686)
- Ariando Ariando (ORCID: https://orcid.org/0000-0002-0598-426X)
- Huajun Liu (ORCID: https://orcid.org/0000-0002-0540-6486)
- Khuong P. Ong (ORCID: https://orcid.org/0000-0003-2835-441X)
- Yeng Ming Lam (ORCID: https://orcid.org/0000-0001-9390-8074)
- Chee Kiang Ivan Tan (ORCID: https://orcid.org/0000-0001-9674-9590)
- Zhi Shiuh Lim
- Baichen Lin (ORCID: https://orcid.org/0000-0003-4601-1664)
- Shengwei Zeng (ORCID: https://orcid.org/0000-0002-3904-0013)
- Samantha Faye Duran Solco (ORCID: https://orcid.org/0000-0002-6335-9972)
- Celine Sim (ORCID: https://orcid.org/0000-0003-4316-1974)
- Zhen Ye (ORCID: https://orcid.org/0000-0002-0687-8901)
- T. Luo (ORCID: https://orcid.org/0009-0007-7273-8791)
- Weifan Cai (ORCID: https://orcid.org/0000-0002-6174-5466)
Institutions
- Agency for Science, Technology and Research (SG)
- National University of Singapore (SG)
- Nanyang Technological University (SG)
- Institute of High Performance Computing (SG)
- Fracture Analysis Consultants (United States) (US)
- Institute of Materials Research and Engineering (SG)
Publication Details
- Journal
- ACS Applied Materials & Interfaces
- Published
- 2025-07-16
- DOI
- https://doi.org/10.1021/acsami.5c09069
- Citations
- 1
- Primary Topic
- Ferroelectric and Piezoelectric Materials
- Type
- article
- Field-Weighted Citation Impact
- 0.52
Funders
- Agency for Science, Technology and Research
- National Research Foundation Singapore
- Ministry of Education - Singapore