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.
Keywords
Cite
@article{arxiv.1305.5416,
title = {New Methods for Calculating the Free Energy of Charged Defects in Solid Electrolytes},
author = {Robert M. Horton and Andrew J. Haslam and Amparo Galindo and George Jackson and Michael W. Finnis},
journal= {arXiv preprint arXiv:1305.5416},
year = {2015}
}