Dynamics of a Perturbed Linear Chain of Atoms

Abstract

Since approximately 1950 an increasing portion of experimental solid state physics research has been concerned with studying defects in crystals. This work uses the code BORN written by Silsbee and Drager to simulate the dynamics of a perturbed linear chain of atoms. Specifically, the dispersion curves for pure and impure monatomic crystal has been obtain. Also the power law dependence of the impurity mode investigated. It has been found that the impurity atom does not alter the shape of the dispersion curve. The effect of the impurity occurs at higher wave vectors, that is, in the lower wavelength limit. As the ratio of the atomic mass of the impurity to the host mass decreases, the maximum angular frequency increases. Also, the power law dependence has been confirmed.

Keywords: Lattice vibration, Dispersion relation, Impurity mode, Defect