Revealing the adhesion, stability and electronic structure of ZrC(111)/SiC(111) interface: A first-principles study

Abstract

The atomic structure and electronic properties of ZrC(111)/SiC(111) interfaces were investigated by first-principles calculations based on density functional theory. Considering three possible stacking sites and four possible terminations, twelve interfaces have been studied. Surface convergence tests show that the non-stoichiometric ZrC(111) slab with 9 atomic layers and the stoichiometric SiC(111) slab with 12 atomic layers exhibited bulk-like interior, and the Zr-terminated ZrC(111) surface is more stable than the C-terminated ZrC(111) surface. Adhesion energy (Wad) calculation shows that a higher bonding strength obtained when the C-terminated ZrC(111) surface is in contact with the SiC(111) surface. Interfacial energies (γint) of the interfaces with C termination at ZrC side (4.08–10.75 J/m2) are larger than those with Zr-termination (0.48–4.46 J/m2) in the whole range of μC−μCbulk. The Zr-/C-terminated hollow-site interface (Zr-HS-C) has the highest stability with the larger Wad and smallest γint. Electronic structure analysis reveals that these interfaces have similar electronic structures, and all had a metallic feature. The ionic and metallic bonds were formed in Zr/Si-terminated center-site (Zr-CS-Si) and Zr/C-terminated hollow-site (Zr-HS-C) interfaces, while covalent and metallic bonds were in the C/Si-terminated top-site (C-TS-Si) and C/C-terminated top-site (C-TS-C) interfaces.