Physico-Chemical nanomaterials science

Graphene-like BeO nanoribbons on the Mo(112) surface
Afanasieva T.V., Fedorus A.G., Naumovets A.G., Rumiantsev D.V.
Physical Electronics Department, Institute of Physics of the NAS of Ukraine. Prospect Nauki, 46, Kyiv-03039, Ukraine. 
E-mail: tetiana.v.afanasieva@gmail.com

In recent years, honeycomb monolayer structures (such as graphene, silicene, germanene, etc.) have attracted great attention due to the prospect of their use in modern nanotechnology. Atomic structure and electronic properties of BeO monolayers were studied both in the form of free 2D nanosheets [1] and in the form of adsorbed films on the Mo(112) support [2,3]. According to the phase diagram calculated by ab initio for (O+Be)/Mo(112) [3], the following honeycomb monolayer modes of BeO should exist: (1x1)BeO/Mo(112) continuous nanosheet and (1xn)BeO/Mo(112) nanoribbons (NRs) of various width n in the range from 2 to 5 substrate periods along the [110] direction. Most of them were experimentally revealed by low-energy electron diffraction (LEED) and Auger electron spectroscopy (AES) methods [3]. The only exception was the n = 2 nanoribbon structure. 
In the present work, we report on the first experimental detection of the (1x2)BeO/Mo(112) nanoribbon structure. The electronic and magnetic properties of BeO nanoribbons on the Mo(112) support and free-standing have been investigated using density functional theory (DFT) calculations. The energetics of the growth of one-dimensional graphene-like BeO structures on the Mo(112) surface have been analyzed. Both types of BeO nanoribbons adsorbed on the Mo(112) support: zigzag edged (ZBeO) and O-terminated (O-ZBeO) NRs have been found to be metallic. Edge metallization and ferromagnetism of the BeO nanoribbons adsorbed on the Mo(112) support and free-standing are discussed.

1.	Zheng H., Li X.-B., Chen N.-K., Xie S.-Y., Tian W. Q., Chen Y., Xia H., Zhang S. B., Sun H.-B. Monolayer II-VI semiconductors: A first-principles prediction // Phys. Rev. B.-2015.-92.-P. 115307.
2.	Afanasieva, T. V., Fedorus, A. G., Rumiantsev, D. V., Yakovkin, I. N. Honeycomb BeO monolayer on the Mo(112) surface: LEED and DFT study // Applied Surface Science.-2018.-428.-P. 815–818.
3.	Afanasieva, T. V., Fedorus A.G., Naumovets A.G., Rumiantsev D.V. Coadsorbed oligolayers of beryllium and oxygen on molybdenum (112) surface: formation and chemical composition, atomic structure and evaporation // Surface Science.-2019.-682.-P. 14-24.