Nature Communications 13, 5903 (2022)
Mengjiao Han#, Cong Wang#, Kangdi Niu, Qishuo Yang, Chuanshou Wang, Xi Zhang, Junfeng Dai, Yujia Wang, Xiuliang Ma, Junling Wang, Lixing Kang*, Wei Ji* Junhao Lin*
Abstract
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 Bi2TeO5 grown by chemical vapor deposition, where spontaneous polarization originates from Bi column displacements. We found an intercalated buffer layer consist ofmixed 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 Bi2TeO5 offer insights into the manipulation of functionalities in van der Waals materials for future nanoelectronics.
