• Kabir, Ahsanul
• Esposito, Vincenzo

Abstract

Cerium oxide is rendered as a key-material for electrochemical devices e.g. electrolytes, anodes, and other solid-state electrochemical cells. The ionic conductivity of these oxides is controlled by the dopant type/charge, more specifically with the microstructure and dopant configuration at the blocking barrier. These are mainly associated with solid-state mass diffusion phenomena that control the material assembling at the atomic scale. In this study, we explore the mechanisms constructing the ionic conductivity blocking barrier effects as a function of dopant type/concentration. These are the result of mass diffusion effects involved in the microstructural consolidation mechanisms from nanoscaled particles to continuum ceramic dense layers. Our experimental results show that ionic conductivity blocking effects are the net result of a combination of defectcations configurations controlled by a multifold overlapping of dopant concentration, cation sizes, electrostatic interactions and density of cation diffusion migration paths. We observe that conductivity can be maximized by tailoring the ceria solid-solutions with strong electrostatic-elastic interaction, allowing local enrichment of solute content. Such effect also leads to steady electromechanical properties at low temperatures, highlighting the impact of designing of microstructural features in tuning characteristic properties in electroceramics.

Topics

• density
• impedance spectroscopy
• microstructure
• Oxygen
• defect
• ceramic
• Cerium