Absence of topological β-antimonene and growth of α-antimonene on noble metal Ag(111) and Cu(111) surfaces
Ping Zhang, Chen Ma, Shaoxiang Sheng, Huiru Liu, Jisong Gao, Zijia Liu, Peng Cheng, Baojie Feng, Lan Chen, Kehui Wu
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.