Protonic Conduction Properties of Nanostructured Gd-doped CeO2 at Low Temperatures

Abstract

The electrical properties of nanostructured Gd-doped CeO2 (n-GDC) as a function of temperature and water partial-pressure were investigated using ac and dc measurements. For n-GDC, protonic conductivity prevails under wet condition and at low temperatures (< 200 degrees C), while oxygen ionic conductivity occurs at high temperatures (>200 degrees C) under both dry and wet conditions. The grain boundaries in n-GDC were highly selective, being conductive for protonic transport but resistive for oxygen ionic transport. The protonic conductivity reaches about 4 x 10(-7) S/cm at room temperature (RT).