Coexistence of α and β Antimonene Phases on a W(110) Substrate

Antimonene (2D-Sb) nanostructures were synthesized on a W(110) substrate by using the molecular beam epitaxy method. By carefully controlling the W(110) substrate temperature during Sb deposition, isolated islands of the α-Sb and β-Sb antimonene allotropes were simultaneously formed on the surface. Antimonene growth was followed using low-energy electron microscopy (LEEM), revealing that α-Sb islands are a single-layer thick and formed by mirror domains with a fixed epitaxial relation to the W(110) substrate. In contrast, the β-Sb phase formed single-domain, multilayered nanostructures that were randomly rotated on the sample surface. Quantum size effect analysis of these two-dimensional (2D) nanostructures indicates notable differences in the electronic properties between the two systems. The coexistence of α-Sb and β-Sb phases suggests the potential for the formation of lateral (in-plane) heterostructures consisting of side-connected allotrope islands.