Phonon Dispersion Relationship and Oxygen Isotope Effect in Superconductor LaFeAsO

In this paper we calculate ab initially the phonon dispersion relationship of the superconductor LaFeAsO and investigate a main property in the superconductor, the oxygen isotope effect. Based on this phonon dispersion relationship, we find the fact that an important reason of the oxygen isotope effect is connected with the phonon. This result agrees well with the experimental data where the power index of the oxygen isotope effect in the superconductor LaFeAsO is small.
Comment: 10 pages, 2 figures, accepted to be published in Int. J. Mod. Phys. B