Fundamental properties of parallelogram graphene nanoflakes: A first principle study

A first principle study with the density functional theory method has carried for parallelogram graphene nanoflakes. In this work, we used ABINIT package to calculate the fundamental properties of parallelogram graphene nanoflakes in the armchair and zigzag types, due to the increase of the number of atoms. The effect of defect for these characters in each type is also presented. Depend on the calculation results, the bandgap of parallelogram graphene nanoflakes only exists in armchair types with the largest bandgap of 0.021 eV for 54 atoms, while the zigzag types have no bandgap. Based on these results, it can be said that the properties of parallelogram graphene nanoflakes were semimetal. In addition, the density of state results shows that the magnetic properties of parallelogram graphene nanoflakes were nonmagnetic since the symmetrical properties between the density of states in spin up and spin down. Based on the results study of defect effect, it was found that the defect only affected the bandgap, but not the magnetic properties. (C) 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 7th International Conference of Advanced Materials Science and Technology 2019.