Ionic Transport Properties in Nanocrystalline Ce 0.8A 0.2O 2-δ (with A = Eu, Gd, Dy, and Ho) Materials

Abstract

The ionic transport properties of nanocrystalline 20 mol% Eu, Gd, Dy, and Ho doped cerias, with average grain size of around 14 nm were studied by correlating electrical, dielectric properties, and various dynamic parameters. Gd-doped nanocrystalline ceria shows higher value of conductivity (i. e., 1. 8 × 10 -4 S cm -1 at 550°C) and a lower value of association energy of oxygen vacancies with trivalent dopants Gd 3+ (i. e., 0. 1 eV), compared to others. Mainly the lattice parameters and dielectric constants (ε ∞) are found to control the association energy of oxygen vacancies in these nanomaterials, which in turn resulted in the presence of grain and grain boundary conductivity in Gd- and Eu-doped cerias and only significant grain interior conductivity in Dy- and Ho-doped cerias. © The Author(s) 2010.