Absence of topological β-antimonene and growth of α-antimonene on noble metal Ag(111) and Cu(111) surfaces

Abstract

Antimonene is a promising two-dimensional material predicted to host intriguing properties. Recent works have claimed the successful preparation of \ensuremath{\beta}-antimonene on noble metal surfaces, including Ag(111) and Cu(111). However, as scanning tunneling microscopy gives only the topographic information, the possibility of surface alloying for the claimed \ensuremath{\beta}-antimonene remains elusive. In this work, by scanning tunneling spectroscopy and in situ Raman spectroscopy measurements, we provide compelling evidence that the ``\ensuremath{\beta}-antimonenes'' on Ag(111) and Cu(111) reported in previous studies are both surface alloys, namely, ${\mathrm{Ag}}_{2}\mathrm{Sb}$ and ${\mathrm{Cu}}_{2}\mathrm{Sb}$. Thus, \ensuremath{\beta}-antimonene does not exist on these substrates. Instead, we find that \ensuremath{\alpha}-antimonene can be grown on both alloy surfaces, with different substrate-induced strain modulation effects. Our work not only clarifies the growth dynamics of Sb on Ag(111) and Cu(111) but also provides two model systems to realize \ensuremath{\alpha}-antimonene with tunable strains.