Simulation of the structure and electronic properties of fluorographene polymorphs formed on the basis of 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, M.E.^1 ; Chernov, V.M.^1 ; Belenkov, E.A.^1

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

454001, Russia^1

关键词: Ab initio calculations;    Calculated values;    Density functional theory methods;    Generalized gradient approximations;    Minimum value;    Polytypes;    Structural type;    Sublimation energy;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/537/2/022058/pdf
DOI  :  10.1088/1757-899X/537/2/022058

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

As a result of a theoretical analysis of the possible structure of polymorphic varieties of compounds obtained from the fluorination of L4-8 graphene, the possibility of existence of 6 main structural varieties of CF-L4-8 layers is established (T1-T6 structural types). Ab initio calculations of these layers were performed by the density functional theory method using the generalized gradient approximation. As a result of the calculations, it was established that only five polytypes have a stable structure except for the T3 type layer. The crystal lattices of CF-L4-8 compounds are tetragonal for the T1 - T5 types, and for the T6 type crystal lattice is orthorhombic. The sublimation energies of CF-L4-8 polymorphs of fluorographene vary in the range of 13.36 to 14.09 eV/(CF), which is slightly less than the calculated value of this parameter (14.32 eV/(CF)) for experimentally synthesized CF-L6 fluorographene of T1-type. The maximum band gap, equal to 4.96 eV, is observed for the T2 type layer, and the minimum value (3.05 eV) corresponds to the fluorographene layer of the T3 type.