Lead overlayer dynamics on Ni(111)

Ultrathin lead films on metallic and semiconductor substrates are technologically demanded and actively studied by different experimental and theoretical methods. The formation of these films gives rise to new adsorbate-induced electron states and vibrational modes. The dynamical properties of atoms on surfaces depend sensitively on their bonding environment and thus provide valuable insight into the local geometry and chemical bonding at the boundary of a solid. In this paper, the vibrational properties of the , (3 × 3) and (4 × 4) overlayers formed by the adsorption of 1/3, 4/9, and 9/16 Pb ML, respectively, on the Ni(111) surface were studied for the first time. The surface relaxations, phonon modes and the local density of states were analyzed. We revealed the role of substrate dynamics in the stability of the Pb/Ni(111) system at submonolayer Pb adsorption.

Surface Dynamics on submonolayer Pb/Cu(001) surfaces

The interplay of atomic structure and phonon spectra in variety of two dimensional phases forming at submonolayer Pb adsoption on the Cu(001) surface has been investigated using embedded atom method...

Phonons on Cu(001) surface covered by submonolayer alkali metals

We present a theoretical investigation of the structural and vibrational properties of ordered 2D phases formed by the Li, Na and K atoms on the Cu[Formula: see text] surface. The lattice relaxation, phonon dispersions and polarization of vibrational modes as well as the local density of states are calculated using the embedded-atom method. The obtained structural parameters and vibrational frequencies are in close agreement with available experimental results.

Vibrational dynamics within the embedded-atom-method formalism and the relationship to Born-von-Kármán force constants

We derive expressions for the dynamical matrix of a crystalline solid with total potential energy described by an embedded-atom-method (EAM) potential. We make no assumptions regarding the number of atoms per unit cell. These equations can be used for calculating both bulk phonon modes as well the modes of a slab of material, which is useful for the study of surface phonons. We further discuss simplifications that occur in cubic lattices with one atom per unit cell. The relationship of Born-von-Kármán (BvK) force constants-which are readily extracted from experimental vibrational dispersion curves-to the EAM potential energy is discussed. In particular, we derive equations for BvK force constants for bcc and fcc lattices in terms of the functions that define an EAM model. The EAM-BvK relationship is useful for assessing the suitability of a particular EAM potential for describing vibrational spectra, which we illustrate using vibrational data from the bcc metals K and Fe and the fcc metal Au.