Oxide-ion conduction and dielectric relaxations in Ca-stabilized ZrO₂

Abstract

The dielectric properties of Ca-stabilized ZrO₂ (Zr_0.9Ca_0.1O_2-δ, 10CSZ) which is an oxide ion conductor were investigated. Numerical analyses for the frequency dependence of dielectric constant (ε_r′) and dielectric loss factors (ε_r″) revealed that the dielectric properties were made up of Debye-type polarization due to dopant-vacancy associates [Ca_zr″-V_o¨] and interfacial polarization at electrolyte-electrode. Two Debye-type relaxations were observed. This result implies the existence of two dopant-vacancy associates with different distances. Moreover, by using the dielectric constants obtained from the numerical analysis, the frequency dependences of ac conductivity (σ_ac) and dielectric loss tangent (tanδ) were also explained.