Diffusion Study for α‐RbAg4I5 System by Molecular Dynamics

The RbAg4I5 compound is a typical fast ion conductor. Several theoretical models for explaining this transport ion dynamic have been proposed. However, there are few studies reported on computer modeling. Herein, to study the diffusion of cation mobility, classical molecular dynamic (MD) simulations...

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Bibliographic Details
Published in:physica status solidi (b) 2020-06, Vol.257 (6), p.n/a
Main Authors: Burbano, Juan C., Peña Lara, Diego, Correa, Hernando
Format: Article
Language:English
Subjects:
microcanonical ensembles
molecular dynamics simulations
RbAg4I5
superionic conductors
Online Access:Get full text
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Summary:The RbAg4I5 compound is a typical fast ion conductor. Several theoretical models for explaining this transport ion dynamic have been proposed. However, there are few studies reported on computer modeling. Herein, to study the diffusion of cation mobility, classical molecular dynamic (MD) simulations are conducted. The interstitial Ag1, Ag2, and Ag4 sites present high occupancy sites, where their activation energy is of the order of thermal energy, providing channels of high mobility. About 60.13% of the ions have a preference to occupy the Ag1 site, 27.89% for the Ag2 site with no apparent distinction for the jump between any of them, 10.26% for the Ag4 site, and a lower occupancy probability for the others, according to experimental data. Jump diffusion mechanism in α‐RbAg4I5 is a collective phenomenon where one cation is pushed to adjacent free sites due to the close presence of other ions of the same species, following channels Ag1→Ag2→Ag1. The results of MD show advantaged paths to Ag‐ion transport, which agrees with experimental data. This fact makes its study highly relevant to improve the understanding of the superionic state. Molecular dynamics simulations, studying the diffusion of cation mobility, are conducted. The interstitial Ag1, Ag2, and Ag4 sites present a high occupancy number, providing channels of high mobility. About 60.13% of the ions have a preference to occupy Ag1, 27.89% for Ag2, 0.26% for Ag4, and lower occupancy probability for others, according to experimental data.
ISSN:0370-1972
1521-3951
DOI:10.1002/pssb.201900730