2025-03-27 シンガポール国立大学（NUS）
Discoveries of superconducting oxides and their critical-temperature at ambient pressure.
＜関連情報＞
- https://news.nus.edu.sg/nus-physicists-copper-free-high-temperature-superconducting-oxide/
- https://www.nature.com/articles/s41586-025-08893-4
正孔ドープSmNiO2における40K付近の常圧バルク超伝導 Bulk superconductivity near 40 K in hole-doped SmNiO2 at ambient pressure
S. Lin Er Chow,Zhaoyang Luo & A. Ariando
Nature Published:20 March 2025
DOI:https://doi.org/10.1038/s41586-025-08893-4（An unedited version）
Abstract
The discovery of superconductivity in the Ba-La-Cu-O system (the cuprate) in the 30 K range marked a significant breakthrough, which inspired extensive explorations of oxide based layered superconductors to identify electron pairing with higher critical temperatures (Tc)1. Despite recent observations of superconductivity in nickel-oxide-based compounds (the nickelates), evidence of Cooper pairing above 30 K in a system that is isostructural to the cuprates, but without copper, at ambient pressure and without lattice compression, has remained elusive2–5. Here, we report superconductivity with a Tc approaching 40 K under ambient pressure in the d9-x hole-doped, late rare-earth infinite-layer nickel oxide (Sm-Eu-Ca-Sr)NiO2 thin films with negligible lattice compression, supported by observations of a zero resistance state at 31 K and the Meissner effect. The material can be synthesized with essentially no Ruddlesden–Popper type structural defects, exhibiting ultralow resistivity of ~ 0.01 mΩ∙cm with a residual-resistivity-ratio of up to 10. Our findings demonstrate the potential of achieving high-temperature superconductivity using strongly correlated d-electron metal oxides beyond copper as the building blocks for superconductivity, offering a promising platform for further exploration and understanding of high-temperature Cooper pairing.
