Superionicity inNa3PO4: A molecular dynamics simulation

Abstract

Fast ionic conduction in solid ${\mathrm{Na}}_3{\mathrm{PO}}_4$ is studied by use of molecular dynamics simulation based on the modified $\mathrm{Lu}$-Hardy approach. We obtain reasonable agreement with experiment for the structural transition and diffusion of the sodium ions. All the sodium ions are found to contribute comparably to the high ionic conductivity. The results of the simulation are discussed in terms of the relative magnitude of the two proposed transport mechanisms: percolation and paddle-wheel. It appears to us that the percolation mechanism dominates the sodium diffusion.