2025-08-01 東京科学大学
図1. LiNbO2から2H-NbO2を合成するストラテジー
＜関連情報＞
- https://www.isct.ac.jp/ja/news/xe59totnsa2v
- https://www.isct.ac.jp/plugins/cms/component_download_file.php?type=2&pageId=&contentsId=1&contentsDataId=2008&prevId=&key=59985de862947e4f7bd38f0ec771e324.pdf&fileName=sciencetokyopr20250801-souma
- https://pubs.acs.org/doi/10.1021/acsnano.5c05513
強く相関したファンデルワールス酸化物：2H-NbO2 Strongly Correlated van der Waals Oxide: 2H-NbO2
Aya Sato,Takuto Soma,Hiroshi Kumigashira,Kohei Yoshimatsu,and Akira Ohtomo
ACS Nano Published: July 18, 2025
DOI:https://doi.org/10.1021/acsnano.5c05513
Abstract
Two-dimensional (2D) materials are attracting attention as an advanced class of materials. However, despite the strongly correlated electron systems exhibiting emergent properties, transition metal oxides are not recognized as 2D materials due to their infrequent van der Waals (vdW) crystal structures. Herein, we present a synthesis route for a vdW 2H-type transition metal dioxide, 2H-NbO2, via a soft-chemical approach from the only 2H-type layered oxide LiNbO2. By combining epitaxially stabilized thin films with a nanoscale thickness and solvothermal reaction, we successfully deintercalated Li, exceeding the bulk limit, while maintaining the single-crystal nature. We demonstrate that the synthesized 2H-NbO2 is a correlated insulator with a half-filled single band, which endows exotic superconductivity to Li1–xNbO2, whose quantum critical phase diagram has similarities to those of cuprates and Moiré superlattices. Our findings indicate that “strongly correlated vdW oxides” could be an approach for introducing Mott physics to 2D systems and a key that connects each research field.
