title: New methods for calculating the free energy of charged defects in solid electrolytes.
abstract: A methodology for calculating the contribution of charged defects to the configurational free energy of an ionic crystal is introduced. The temperature-independent Wang-Landau Monte Carlo technique is applied to a simple model of a solid electrolyte, consisting of charged positive and negative defects on a lattice. The electrostatic energy is computed on lattices with periodic boundary conditions, and used to calculate the density of states and statistical-thermodynamic potentials of this system. The free energy as a function of defect concentration and temperature is accurately described by a regular solution model up to concentrations of 10% of defects, well beyond the range described by the ideal solution theory. The approach, supplemented by short-ranged terms in the energy, is proposed as an alternative to free energy methods that require a number of simulations to be carried out over a range of temperatures.
authors: Department of Physics, Imperial College, London, SW7 2AZ, UK. Department of Materials, Imperial College, London, SW7 2AZ, UK.
authors: Robert M
authors: RM
authors: Horton
authors: Andrew J
authors: AJ
authors: Haslam
authors: Amparo
authors: A
authors: Galindo
authors: George
authors: G
authors: Jackson
authors: Michael W
authors: MW
authors: Finnis