Structures of α-Bi_xSb_1–x Alloys Formed on the TiSe₂ Substrates

Abstract

The scientific breakthrough in Xenes has attracted extensive attention due to their exotic physical properties and potential applications. Bismuthene and antimonene, the representative members of group-VA Xenes, share similar crystal structures and fantastic physical properties, and their alloys also exhibit rich physical properties, by adjusting stoichiometry. However, the synthesis of two-dimensional (2D) Bi x Sb 1−x alloys with different phases has been rarely addressed and their exact surface structures remain unclear. In this work, we report on seven types of α-Bi x Sb 1−x alloys grown on TiSe 2 substrates via molecular beam epitaxy (MBE) and low-temperature scanning tunneling microscopy (LT-STM). Such plentiful alloys were formed due to the chemical and interfacial strain. Combined with Vegard's law, the exact stoichiometries of those α-Bi x Sb 1−x alloys were obtained. Our work clarifies the structures of the 2D Bi x Sb 1−x alloys, shedding light on the synthesis of alloys for intriguing properties and potential applications.