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Dean JM, Coles SW, Saunders WR, McCluskey AR, Wolf MJ, Walker AB, Morgan BJ. Overscreening and Underscreening in Solid-Electrolyte Grain Boundary Space-Charge Layers. PHYSICAL REVIEW LETTERS 2021; 127:135502. [PMID: 34623837 DOI: 10.1103/physrevlett.127.135502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
Polycrystalline solids can exhibit material properties that differ significantly from those of equivalent single-crystal samples, in part, because of a spontaneous redistribution of mobile point defects into so-called space-charge regions adjacent to grain boundaries. The general analytical form of these space-charge regions is known only in the dilute limit, where defect-defect correlations can be neglected. Using kinetic Monte Carlo simulations of a three-dimensional Coulomb lattice gas, we show that grain boundary space-charge regions in nondilute solid electrolytes exhibit overscreening-damped oscillatory space-charge profiles-and underscreening-decay lengths that are longer than the corresponding Debye length and that increase with increasing defect-defect interaction strength. Overscreening and underscreening are known phenomena in concentrated liquid electrolytes, and the observation of functionally analogous behavior in solid electrolyte space-charge regions suggests that the same underlying physics drives behavior in both classes of systems. We therefore expect theoretical approaches developed to study nondilute liquid electrolytes to be equally applicable to future studies of solid electrolytes.
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Affiliation(s)
- Jacob M Dean
- Department of Chemistry, University of Bath, Claverton Down BA2 7AY, United Kingdom
- The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, United Kingdom
| | - Samuel W Coles
- Department of Chemistry, University of Bath, Claverton Down BA2 7AY, United Kingdom
- The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, United Kingdom
| | - William R Saunders
- Department of Physics, University of Bath, Claverton Down BA2 7AY, United Kingdom
| | - Andrew R McCluskey
- Department of Chemistry, University of Bath, Claverton Down BA2 7AY, United Kingdom
- European Spallation Source ERIC, P.O. Box 176, SE-221 00, Lund, Sweden
| | - Matthew J Wolf
- Department of Physics, University of Bath, Claverton Down BA2 7AY, United Kingdom
| | - Alison B Walker
- Department of Physics, University of Bath, Claverton Down BA2 7AY, United Kingdom
| | - Benjamin J Morgan
- Department of Chemistry, University of Bath, Claverton Down BA2 7AY, United Kingdom
- The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, United Kingdom
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