First-Principles Study of Molecule/Al Interfaces

Abstract

The structural and electronic properties of C_nH_2n+2/Al(110) interfaces (n=5) have been studied by first-principles calculations using a plane-wave pseudopotential method coupled with an efficient electronic minimization scheme for large systems. We have examined the stability of vertical and parallel adsorption of a C₅H₁₂ molecule on an Al(110) surface for various adsorption sites and initial interface distances. It has been found that image interactions between the C-H polar bonds and the metal surface with physorption characters dominate the interfacial interactions for both the vertical and parallel cases of the C₅H₁₂/Al interfaces. However, for the C₅H₁₁ molecule with a dehydrogenated terminal C atom, we have observed the formation of a strong interfacial C-Al bond with both covalent and ionic characters.