Modeling the series of (n x 2) Si-rich reconstructions of beta-SiC(001): a prospective atomic wire?

Abstract

We perform ab initio plane wave supercell density functional calculations on three candidate models of the (3 x 2) reconstruction of the beta-SiC(001) surface. We find that the two-adlayer asymmetric-dimer model (TAADM) is unambiguously favored for all reasonable values of Si chemical potential. We then use structures derived from the TAADM parent to model the silicon lines that are observed when the (3 x 2) reconstruction is annealed (the (n x 2) series of reconstructions), using a tight-binding method. We find that as we increase n, and so separate the lines, a structural transition occurs in which the top addimer of the line flattens. We also find that associated with the separation of the lines is a large decrease in the HOMO-LUMO gap, and that the HOMO state becomes quasi-one-dimensional. These properties are qualititatively and quantitatively different from the electronic properties of the original (3 x 2) reconstruction.

22 pages, including 6 EPS figures

References in corpus (1)

• Theoretical study of the (3x2) reconstruction of beta-SiC(001)

Cited by in corpus (4)

• Molecular dynamics study of the fragmentation of silicon doped fullerenes
• Cubic silicon carbide under tensile pressure: Spinodal instability
• Quantum nuclear motion in silicene: Assessing structural and vibrational properties through path-integral simulations
• Elastic properties of silicene: Spinodal instabilities