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The Intrinsic Structural Resistance of a Grain Boundary to Transverse Ionic Conduction
Author(s) -
GenreithSchriever Annalena R.,
Parras Jana P.,
Heelweg Henrik J.,
De Souza Roger A.
Publication year - 2020
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.202000773
Subject(s) - grain boundary , ionic conductivity , materials science , condensed matter physics , crystallite , chemical physics , ionic bonding , thermal conduction , space charge , ion , ionic potential , molecular dynamics , resistive touchscreen , charge carrier , chemistry , electron , microstructure , composite material , electrolyte , physics , computational chemistry , metallurgy , electrical engineering , organic chemistry , electrode , quantum mechanics , engineering
Ion transport across grain boundaries in diverse polycrystalline ionic conductors is often found to be hindered. Such behaviour is commonly attributed to the presence of a highly resistive second phase or to the presence of space‐charge zones, in which mobile charge carriers are strongly depleted. One other possible cause – the severe perturbation of the crystal structure within the grain‐boundary core – is widely ignored. Employing molecular dynamics (MD) simulations of the model Σ5(310)[001] grain boundary in fluorite‐structured CeO 2 , we demonstrate an approach to extract the intrinsic structural resistance of a grain boundary (to ionic transport across it), and we determine this excess resistance as a function of temperature. Compared with space‐charge resistances predicted for a dilute solution of charge carriers the structural resistance of this interface is orders of magnitude smaller at temperatures below T ≈1000 K but at T >1200 K it is no longer negligible.