Phonon Dispersion Relation of Lead (Pb) and Palladium (Pd)
Omamoke O. E. Enaroseha, P. O. Osuhor, Obed Oyibo
Abstract
The Computational theoretical techniques were applied in the investigation of Phonon Dispersion of Lead (Pb) and Palladium (Pd). The first principle technique makes use of the density functional theory as implemented by quantum expresso as well as interatomic force constant (IFC) techniques (Born-von Jarman) which was extended to a higher number of neighbors than what is available in the literature were employed in this research. The results obtained show that the local density approximation (LDA) phonon dispersion slightly overestimates experimental results whereas the generalized gradient approximation (GGA) gives a slightly lower frequency. However, there was a negligible improvement in the quality of fit in the lead when the ninth neighbor (1 - 9NN) interaction was introduced.