Year: 2020
Type: article
Abstract: 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 CeO2, 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.
Source: ChemElectroChem
Institution: RWTH Aachen University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,500
Award: G4928488920
OpenAlex ID: W3047526320