Vibrational analysis of ion dynamics in Ag β-alumina by Raman and molecular dynamics simulation

The Raman spectra of single crystal Ag β-alumina have been measured at room temperature. The interatomic potential was evaluated by a non-linear least square fitting between phonon eigenvalues from Raman and dynamical matrix calculation. Using the obtained pair-potentials, the MD simulation was performed. In order to understand the many-body effects for the fast ion conduction in super ionic conductor, the three kinds of Ag-Ag interaction energies were assumed. The potential barrier height for jump diffusion depends on the magnitude of the repulsive force between mobile ions. It gives a new insight into an ion dynamics of super ionic conductor.