Structure, Dynamics and Themodynamics of a metal chiral surface: Cu(532)

Abstract

The structure, vibrational dynamics and thermodynamics of a chiral surface, Cu(532), has been calculated using a local approach and the harmonic approximation, with interatomic potentials based on the embedded atom method. The relaxation of atomic positions to the optimum configuration results in a complex relaxation pattern with strong contractions in the bond length of atoms near the kink and the step site and an equivalently large expansion near the least under-coordinated surface atoms. The low coordination of the atoms on the surface affects substantially the vibrational dynamics and thermodynamics of this system. The local vibrational density of states show a deviation from the bulk behavior that persist down to the 10th layer resulting in a substantial contribution of the vibrational entropy to the excess free energy amounting to about 90 meV per unit cell at 300K.