Speaker
Description
Ab-intio Density Fuctional Theory has been employed to investigate the stabilities of Li< sub >2< /sub >O, Li< sub >2< /sub >S, Li< sub >2< /sub >O< sub >2< /sub > and Li< sub >2< /sub >S< sub >2< /sub > systems. Calculations were carried out utilizing Plane-wave Pseudopotential method within GGA-PBE using VASP CODE. We found good agreement between predicted data and experimental data of lattice parameters . The elastic constant for Li< sub >2< /sub >O, Li< sub >2< /sub >S accord well with experimental results and those of Li< sub >2< /sub >O< sub >2< /sub > and Li< sub >2< /sub >S< sub >2< /sub > are reasonably predicted, and satisfied stability conditions. Phonon dispersion of Li< sub >2< /sub >O and Li< sub >2< /sub >S compare well with those obtained from neutron scattering experiments. We predicted phonon dispersion of Li< sub >2< /sub >O< sub >2< /sub > suggest that the structure is stable, while those of Li< sub >2< /sub >S< sub >2< /sub >< sub >2< /sub > display soft modes along along Г direction hence suggesting structural instabilities. Furthermore phonon density of states attribute the instability to the vibrations of the sulphur atoms in the ab plane.
| Level (Hons, MSc, <br> PhD, other)? | MSc |
|---|---|
| Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)? | No |
| Consider for a student <br> award (Yes / No)? | Yes |
