Table 1 Structural parameters of the epitaxial silicene on different metal substrates. The structural phase is shown in the first row. a and a' are the lattice constants of metal substrates and corresponding free-standing silicene in a supercell and Δa is the lattice mismatch between metal and free-standing silicene. Δ is the calculated buckling of silicene. d0 is the equilibrium separation of silicene from various metal surfaces. The binding energy Eb is the energy (per Si atom) required to remove the silicene sheet from the metal surface. G is the formation energy (per Si atom) of epitaxial silicene on metal with bulk Si as the reservoir of Si. Wm and W are the work functions for the clean metal surface and for the metal-supported silicene, respectively. Q is the Mulliken charge per Si atom transferred from silicene to the metal surfaces. The work function of free-standing silicene is 4.48 eV
From: Does the Dirac Cone Exist in Silicene on Metal Substrates?
(√3×√3)Si/(√7×√7)Ir | (√3×√3)Si/(2×2)Mg | (√3×√3)Si/(√7×√7) Cu | (2×2)Si/(√7×√7)Agb | (√3×√3)Si/(√7×√7)Pt | (√3×√3)Si/(√7×√7)Al | (√3×√3)Si/(√7×√7)Au | ||
|---|---|---|---|---|---|---|---|---|
a (Å) | 7.18 | 7.2a | 6.42 | 6.76 | 7.64 | 7.34 | 7.58 | 7.63 |
a' (Å) | 6.70 | 6.70 | 6.70 | 7.73 | 6.70 | 6.70 | 6.70 | |
Δa (%) | 7.2 | −4.1 | 1.0 | −1.2 | 9.6 | 13.2 | 14.0 | |
Δ (Å) | 0.83 | 0.83a | 1.52 | 1.25 | 1.16 | 0.33 | 0.29 | 0.21 |
d0 (Å) | 1.95 | 2a | 2.28 | 1.57 | 1.39 | 1.97 | 2.12 | 1.81 |
Eb (eV) | 1.69 | 1.6a | 0.39 | 0.86 | 0.41 | 1.74 | 0.35 | 0.63 |
G (eV) | 1.10 | −0.20 | 0.27 | −0.19 | 1.15 | −0.24 | 0.04 | |
Wm (eV) | 5.47 | 3.55 | 4.69 | 4.46 | 5.82 | 4.06 | 5.09 | |
W (eV) | 5.05 | 3.98 | 4.45 | 4.36 | 4.55 | 4.12 | 4.56 | |
Q (|e|) | 0.13 | −0.21 | −0.04 | −0.07 | 0.06 | −0.06 | 0.04 | |
