Role of vacancies in the magnetic and electronic properties of SiC nanoribbons: An ab initio study

Using ab initio calculations based on density functional theory, we investigate the effects of vacancies on the electronic and magnetic properties of zigzag SiC nanoribbons (Z-SiCNR). Single (V-C and V-Si) and double (VSiVSi and VSiVC) vacancies are observed to inducemagnetism in Z-SiCNRs. The presence of a single V-Si does not affect the half-metallic behavior of pristine Z-SiCNRs; however, a single V-C leads to a transition from half-metallic to metallic behavior in Z-SiCNRs due to the edge Si p orbitals and the atoms surrounding the vacancy. The interactions of vacancies with foreign impurity atoms (B and N) are also investigated, and it is observed that VSiNC not only suppresses the oscillatory type magnetism of VSiVC but also retains the half-metallic character of the pristine Z-SiCNRs. The defect formation energies of vacancies can be reduced by substitutional B and N atoms. We believe that ferromagnetism is expected if Z-SiCNRs are grown under suitable conditions. DOI: 10.1103/PhysRevB.87.115428