The Effects of the Formation of Stone-Wales Defects on the Electronic and Magnetic Properties of Silicon Carbide Nanoribbons: A First-Principles Investigation

• Published in: Chemphyschem 2013-08, Vol.14 (12), p.2841-2852
• Main Authors: Guan, Jia, Yu, Guangtao, Ding, Xiuling, Chen, Wei, Shi, Zhiming, Huang, Xuri, Sun, Chiachung
• Format: Article
• Language: English
• Subjects: band structures; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Defects; density functional calculations; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic structure of nanoscale materials : clusters, nanoparticles, nanotubes, and nanocrystals; Exact sciences and technology; Magnetic properties and materials; Magnetic properties of nanostructures; nanostructures; Physics; Principles; Silicon carbide; Stone-Wales defects
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.201300097

Detailed first‐principles density functional theory (DFT) computations were performed to investigate the geometries, the electronic, and the magnetic properties of both armchair‐edged silicon carbide nanoribbons (aSiCNRs) and zigzag‐edged silicon carbide nanoribbons (zSiCNRs) with Stone–Wales (SW) defects. SW defects in the center of aSiCNRs can remarkably reduce their band gaps, irrespective of the orientation of the defect, whereas zSiCNRs with SW defects in the center or at the edges exhibit degenerate energies of their ferromagnetic (FM) and antiferromagnetic (AFM) states, in which metallic and half‐metallic behavior can be observed, respectively; half‐metallic behavior can even be observed in both the FM and AFM states simultaneously. Further, it was shown that the formation energies of the SW defects in SiCNRs are orientation dependent, and the formation of edge defects is always favored over the formation of interior defects in zSiCNRs. The possible existence of SW defects in SiCNRs was further validated through exploring the kinetic process of their formation. These findings can be anticipated to provide valuable information in promoting the potential applications of SiC‐based nanomaterials in multifunctional and spintronic nanodevices. Defective by design: On the basis of first‐principles density functional theory, Stone–Wales (SW) defects are found to reduce the band gap of armchair‐edged silicon carbide nanoribbons (SiCNRs); however, these defects do not alter the energy degeneracy of the ferromagnetic (FM) and antiferromagnetic (AFM) states of zigzag‐edged SiCNRs (zSiCNRs), for which metallic/half‐metallic and half‐metallic behavior can be observed, respectively.