Vibrational dynamics and thermodynamics of Ni(977)

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Abstract
We present an analysis of the vibrational density of states and characteristics of some surface vibrational modes of Ni(977), using a real space Green’s function approach with force constants derived from interaction potentials based on the embedded atom method. Changes in the force fields at and near the steps are found to lead to both softening and stiffening of the force constants between the surface atoms, as compared to those on Ni(111). Among the striking features of this vicinal, is a quasi-one-dimensional mode at 3.3 THz that is super localized at the step and a mode at 9.1 THz that has a propagation direction peculiar to this surface. Further, from an examination of the surface thermodynamics of Ni(977) it is seen that only the step and the corner atoms display features that are distinct from those on Ni(111).