Peculiar Structural Phase of a Single-Atom-Thick Layer of Antimony

[Image: see text] Using molecular beam epitaxy, a new structural phase of a single atom thick antimony layer has been synthesized on the W(110) surface. Scanning tunneling microscopy measurements reveal an atomically resolved structure with a perfectly flat surface and unusually large unit cell. The structure forms a well-ordered continuous film with a lateral size in the range of several millimeters, as revealed by low energy electron microscopy and diffraction experiments. The results of density functional theory calculations confirm the formation of a new phase of single-atom-thick antimony film without the buckling characteristic for the known phases of antimonene. The presented results demonstrate a substrate-tuned approach in the preparation of new structural phases of 2D materials.