A Consistent Picture of Charge Distribution in Reduced Ceria Phases

TL;DR

This paper analyzes charge distribution in reduced ceria phases using the bond valence model, showing consistency with existing models and proposing potential low-temperature metallic conductivity in intermediate phases.

Contribution

It demonstrates that the bond valence model aligns with both small polaron and atomistic models for charge distribution in ceria, and suggests new metallic conductivity possibilities.

Findings

BVM is consistent with SPM and atomistic models.

Intermediate phases may exhibit low-temperature metallic conductivity.

Contrasts BVM results with conventional charge distribution models.

Abstract

We consider the implications of the bond valence model (BVM) description of charge distribution in reduced ceria phases (CeO$_{2-x}$)\cite{Shoko2009,Shoko2009b} to the models used to describe electronic and ionic conductivity in these phases. We conclude that the BVM is consistent with both the small polaron model (SPM) and the atomistic models which describe the electronic and ionic conductivities respectively. For intermediate phases, i.e., $x \sim 0.3$, we suggest the possibility of low temperature metallic conductivity. This has not yet been experimentally observed. We contrast the BVM results and the conventional description of charge distribution in reduced ceria phases.