Strain effect on the electronic properties of graphdiyne

In this theoretical study, within the nearest neighbor tight-binding model and Green's function technique, the density of states (DOS), electronic heat capacity (EHC), and Pauli magnetic susceptibility (PMS) of graphdiyne system under different strain values (5%, 9%, and 15%) are calculated and the results are compared with those of a graphdiyne monolayer without any strain. It is observed that with increasing strain, the band gap near the Fermi level of graphdiyne increases monotonously due to the decreased orbital overlap between C atoms. In addition, the intra-bandgaps and the van-Hove singularities are seen in the DOS curves of all systems. These lead to the Schottky anomaly peaks in the EHC and the crossovers in the PMS curves, which are divided into two low and high temperature regions. At vicinity of zero temperatures, with increasing strain, the EHC and PMS decrease. From the theoretical stand point, this phenomenon stems from the proportional relationship of the PMS and EHC with DOS.

Automated summary

In this theoretical study, the density of states (DOS), electronic heat capacity (EHC), and Pauli magnetic susceptibility (PMS) of graphdiyne system under different strain values were calculated using the nearest neighbor tight-binding model and Green's function technique. The results show that with increasing strain, the band gap near the Fermi level of graphdiyne increases monotonously. Additionally, intra-bandgaps and van-Hove singularities were observed in the DOS curves, leading to Schottky anomaly peaks in the EHC and crossovers in the PMS curves.