Xu Xiang, Zhong Tingting, Zuo Nian, Li Zexin, Li Dongyan, Pi Lejing, Chen Ping, Wu Menghao, Zhai Tianyou, Zhou Xing
State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
Department of Physics, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China.
ACS Nano. 2022 May 24;16(5):8141-8149. doi: 10.1021/acsnano.2c01470. Epub 2022 Apr 20.
Two-dimensional (2D) ferroelectrics have attracted intensive attention. However, the 2D ferroelectrics remain rare, and especially few of them represent high ferroelectric transition temperature (), which is important for the usability of ferroelectrics. Herein, CuCrS nanoflakes are synthesized by salt-assisted chemical vapor deposition and exhibit switchable ferroelectric polarization even when the thickness is downscaled to 6 nm. On the contrary, a CuCrS nanoflake shows a as high as ∼700 K, which can be attributed to the robust tetrahedral bonding configurations of Cu cations. Such robustness can be further clarified by a theoretically predicted high order-disorder transition barrier and structure evolution from 600 to 800 K. Additionally, the interlocked out-of-plane (OOP) and in-plane (IP) ferroelectric domains are observed and two kinds of devices based on OOP and IP polarizations are demonstrated.
二维（2D）铁电体已引起广泛关注。然而，二维铁电体仍然很少见，尤其是其中很少有代表高铁电转变温度（ ）的，这对于铁电体的实用性很重要。在此，通过盐辅助化学气相沉积合成了CuCrS纳米片，即使厚度缩小到6纳米，也表现出可切换的铁电极化。相反，CuCrS纳米片显示出高达约700 K的 ，这可归因于Cu阳离子强大的四面体键构型。通过理论预测的高阶无序转变势垒以及600至800 K的结构演变，可以进一步阐明这种稳健性。此外，观察到互锁的面外（OOP）和面内（IP）铁电畴，并展示了基于OOP和IP极化的两种器件。
