The effects of strain and electric field on the half-metallicity of pristine and O-H/C-N-decorated zigzag graphene nanoribbons

摘要

In zigzag graphene nanoribbons (ZGNRs), the spin polarized edge states play a significant role in the electronic structure. The two ferromagnetically ordered edges anti-ferromagnetically coupled with each other, which would result in the half-metallicity under electric field. Given that the strain, external electric field, and edge decorations are the main means of tuning the magnetism and electronic property of one-dimentional materials. It motivates us to study the combine effects on ZGNRs of these methods. So, in present work, the corporate influences of the tensile strain, transverse electric field, and asymmetric edge decoration by -OH and -CN groups on the magnetism and electronic property of 8-ZGNR have been studied using the density functional theory. The calculational results indicate that the arising strain can modulate the response of electronic and magnetic properties to external electric field, improving the magnetism and extending the electric field range in which the ZGNR presents half-metallicity. In addition, the O-H/C-N groups decorated ZGNR possesses a lower critic electric field and a larger electric field range for realizing half-metallicity comparing with the unstrained pristine ZGNR.