Lattice Dynamics of Silicon

Abstract

A phenomenological lattice dynamical model has been developed for the zinc-blendeand diamond structure crystals. The model developed in the present work is anextended valence force field (EVFF) model which takes into account the short rangevalence force field interaction between bonded atoms and central interaction betweennon-bonded atoms. The model also incorporates the long-range coulombic interactionfor zinc-blende crystals which are partially ionic in bonding. EVFF model is applied tolattice vibration of silicon to obtain the phonon dispersion curves, elastic constants,bulk modulus, Debye characteristic temperatures and phonon distribution functionfor silicon. The theoretical values are compared with the experimental results withsatisfactory agreement