Continuously tunable ferroelectric domain width down to the single-atomic limit in bismuth tellurite
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
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 Bi 2 TeO 5 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 Bi 2 TeO 5 offer insights into the manipulation of functionalities in van der Waals materials for future nanoelectronics.