Critical Thickness and Long‐Term Ambient Stability in Superconducting LaPr <sub>2</sub> Ni <sub>2</sub> O <sub>7</sub> Films
The recent observation of ambient-pressure superconductivity in compressively strained (La,Pr)<sub>3</sub>Ni<sub>2</sub>O<sub>7</sub> films marks a significant advance in nickelate superconductivity research. However, their fabrication remains challenging, with reported thickness limited to <6.6 nm and pronounced ambient degradation. In this study, LaPr<sub>2</sub>Ni<sub>2</sub>O<sub>7</sub> films with nominal thicknesses ranging from 3.5 to 23.5 nm are fabricated. Superconductivity is observed in all samples, with a maximum onset transition temperature (T<sub>c</sub>) of 44 K. No systematic correlation between T<sub>c</sub> and film thickness is identified. Angle-dependent T<sub>c</sub> measurements under external magnetic fields and vortex anisotropy analysis indicate 2D superconductivity in all samples. Structural and transport measurements show that superconductivity in LaPr<sub>2</sub>Ni<sub>2</sub>O<sub>7</sub> is confined to within 10 nm of the interface, while thicker films develop a protective (La,Pr)<sub>4</sub>Ni<sub>3</sub>O<sub>10</sub> surface layer that enhances stability. Ex situ amorphous oxide capping layers further suppress superconducting degradation, yielding 10-fold stability enhancement in ultrathin films (3 ≈ 4 nm) and prolonging stability from 30 to more than 100 days in thicker films.
Authors
- Huiqiu Yuan (ORCID: https://orcid.org/0000-0002-9787-4884)
- Junchi Fu
- Dongsheng Song (ORCID: https://orcid.org/0009-0005-2449-2059)
- Chenlu Song (ORCID: https://orcid.org/0000-0003-3499-2872)
- Yanwu Xie (ORCID: https://orcid.org/0000-0002-8447-9455)
- Qi Li (ORCID: https://orcid.org/0000-0002-1702-8347)
- Ye Chen (ORCID: https://orcid.org/0000-0003-3671-2504)
- Meng Zhang (ORCID: https://orcid.org/0000-0001-7609-6393)
- Yanzhi Wang (ORCID: https://orcid.org/0000-0002-3024-7990)
- Ming Qin (ORCID: https://orcid.org/0000-0002-2718-5864)
- Yue Yang (ORCID: https://orcid.org/0009-0002-5932-6358)
- Yuexin Shi
- Yingze Jia
- Zhen Chen (ORCID: https://orcid.org/0009-0007-7842-5446)
Institutions
- Anhui University (CN)
- Chinese Academy of Sciences (CN)
- Hefei University (CN)
- Collaborative Innovation Center of Advanced Microstructures (CN)
- Institute of Physics (CN)
- University of Chinese Academy of Sciences (CN)
- Zhejiang University (CN)
- Nanjing University (CN)
Publication Details
- Journal
- Advanced Materials
- Published
- 2025-10-15
- DOI
- https://doi.org/10.1002/adma.202510394
- Citations
- 2
- Primary Topic
- Magnetic and transport properties of perovskites and related materials
- Type
- article
- Field-Weighted Citation Impact
- 0.85