Lattice Dynamics of Silicon

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