Han Mengjiao, Wang Cong, Niu Kangdi, Yang Qishuo, Wang Chuanshou, Zhang Xi, Dai Junfeng, Wang Yujia, Ma Xiuliang, Wang Junling, Kang Lixing, Ji Wei, Lin Junhao
Department of Physics and Shenzhen Key Laboratory of Advanced Quantum Functional Materials and Devices, Southern University of Science and Technology, Shenzhen, 518055, China.
SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing, 210096, China.
Nat Commun. 2022 Oct 6;13(1):5903. doi: 10.1038/s41467-022-33617-x.
Emerging functionalities in two-dimensional materials, such as ferromagnetism, superconductivity and ferroelectricity, open new avenues for promising nanoelectronic applications. Here, we report the discovery of intrinsic in-plane room-temperature ferroelectricity in two-dimensional BiTeO grown by chemical vapor deposition, where spontaneous polarization originates from Bi column displacements. We found an intercalated buffer layer consist of mixed Bi/Te column as 180° domain wall which enables facile polarized domain engineering, including continuously tunable domain width by pinning different concentration of buffer layers, and even ferroelectric-antiferroelectric phase transition when the polarization unit is pinned down to single atomic column. More interestingly, the intercalated Bi/Te buffer layer can interconvert to polarized Bi columns which end up with series terraced domain walls and unusual fan-shaped ferroelectric domain. The buffer layer induced size and shape tunable ferroelectric domain in two-dimensional BiTeO offer insights into the manipulation of functionalities in van der Waals materials for future nanoelectronics.
二维材料中出现的新功能，如铁磁性、超导性和铁电性，为有前景的纳米电子应用开辟了新途径。在此，我们报告了通过化学气相沉积生长的二维BiTeO中本征面内室温铁电性的发现，其中自发极化源于Bi柱位移。我们发现一个由混合Bi/Te柱组成的插层缓冲层作为180°畴壁，这使得极化畴工程变得容易，包括通过固定不同浓度的缓冲层来连续调节畴宽度，以及当极化单元固定到单个原子柱时甚至发生铁电-反铁电相变。更有趣的是，插层的Bi/Te缓冲层可以相互转化为极化的Bi柱，最终形成串联的梯田状畴壁和不寻常的扇形铁电畴。二维BiTeO中缓冲层诱导的尺寸和形状可调的铁电畴为未来纳米电子学中范德华材料功能的操纵提供了见解。
