Structure and electronic properties of graphyne polymorphs formed from 4-8 graphene

International Workshop "Advanced Technologies in Material Science, Mechanical and Automation Engineering – MIP: Engineering – 2019"

材料科学;机械制造;原子能学

Belenkov, E.A.^1 ; Mavrinskii, V.V.^2 ; Greshnyakov, V.A.^1 ; Brzhezinskaya, M.M.^3

Chelyabinsk State University, 129, Bratiev Kashirinykh Str., Chelyabinsk

454001, Russia^1

Nosov Magnitogorsk State Technical University, Lenin Str., 38, Magnitogorsk

455000, Russia^2

Helmholtz-Zentrum Berlin Für Materialien und Energie, 1, Hahn-Meitner-Platz, Berlin

14109, Germany^3

关键词: Carbon material;    Density functional theory in the generalized gradient approximation;    Electronic characteristics;    Geometric optimization;    Graphene layers;    Graphite layers;    Normal condition;    Sublimation energy;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/537/2/022070/pdf
DOI  :  10.1088/1757-899X/537/2/022070

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The structure and electronic characteristics of new polymorphic varieties of graphyne, obtained on the basis of the L4-8 graphene layer, are investigated by the method of the density functional theory in the generalized gradient approximation. Theoretically, seven types of graphite were built: α-L4-8-, β1-L4-8-, β2-L4-8-, β2-L4-8-, γ1-L4-8-, γ2-L4-8-, and γ3-L4-8-graphyne. However, as a result of geometric optimization, the structure of two graphyne layers (γ2-L4-8-, and γ3-L4-8-graphyne) was transformed into a graphene structure. The sublimation energy of the remaining graphite layers is in the range from 6.63 to 6.79 eV per atom. This energy is lower than the sublimation energy of graphene layers, however, it is in the range of sublimation energies characteristic of carbon materials that are stable under normal conditions. The band gap for the graphyne layers is zero or tending to zero, therefore the properties of the layers must be metallic.