2023-08-07 ライス大学
◆この複合材料は、熱伝導率が低く、電子デバイスの断熱材として機能する可能性を持ち、光学的特性も予想以上に大きな変化を示しました。突然の高温処理により、ヘキサゴナルホウ素窒化物への変化が確認され、新たな条件下でホウ素窒化物のバリエーションが現れることが示唆されました。
◆この研究は、ホウ素窒化物のカスタマイズ可能な特性を開拓する可能性を示し、次世代テクノロジーに革命をもたらす可能性を秘めています。
＜関連情報＞
- https://news.rice.edu/news/2023/rice-labs-boron-nitride-composite-could-be-useful-advanced-technology-applications
- https://pubs.acs.org/doi/full/10.1021/acs.nanolett.3c01537
六方晶/立方晶窒化ホウ素ナノコンポジットの相安定性 Phase Stability of Hexagonal/Cubic Boron Nitride Nanocomposites
Abhijit Biswas, Rui Xu, Joyce Christiansen-Salameh, Eugene Jeong, Gustavo A. Alvarez, Chenxi Li, Anand B. Puthirath, Bin Gao, Arushi Garg, Tia Gray, Harikishan Kannan, Xiang Zhang, Jacob Elkins, Tymofii S. Pieshkov, Robert Vajtai, A. Glen Birdwell, Mahesh R. Neupane, Bradford B. Pate, Tony Ivanov, Elias J. Garratt, Pengcheng Dai, Hanyu Zhu, Zhiting Tian, and Pulickel M. Ajayan
Nano Letters July 25, 2023
DOI:https://doi.org/10.1021/acs.nanolett.3c01537
Abstract
Boron nitride (BN) is an exceptional material, and among its polymorphs, two-dimensional (2D) hexagonal and three-dimensional (3D) cubic BN (h-BN and c-BN) phases are most common. The phase stability regimes of these BN phases are still under debate, and phase transformations of h-BN/c-BN remain a topic of interest. Here, we investigate the phase stability of 2D/3D h-BN/c-BN nanocomposites and show that the coexistence of two phases can lead to strong nonlinear optical properties and low thermal conductivity at room temperature. Furthermore, spark-plasma sintering of the nanocomposite shows complete phase transformation to 2D h-BN with improved crystalline quality, where 3D c-BN possibly governs the nucleation and growth kinetics. Our demonstration might be insightful in phase engineering of BN polymorph-based nanocomposites with desirable properties for optoelectronics and thermal energy management applications.
