No CrossRef data available.
Article contents
Electrical Relaxation Studies in Fluorite Oxides
Published online by Cambridge University Press: 21 February 2011
Abstract
Electric relaxation in CeO2-M203 (M34 sY3+, La3+) solid solutions has been investigated as a function of temperature (373K-673K) using the electric modulus formalism in the frequency range 5 to 107Hz. Two relaxation processes are observed in dilute solid solutions. The low frequency process is identified as a long range migration of free oxygen-vacancies (Process A) and the high frequency process is due to reorientation relaxation of the (MceVo) charged associates (Process B). The relaxation process is analysed using a non-exponential decay function, ø(t)=exp[-(t/τo)B] for O<β≤1, of the electric field. The observed activation enthalpy minimum as a function of dopant concentration for the Process A is explained using the concept of incomplete dissociation of oxygen-vacancies from (MceVo) defect associates and the formation of higher-order defect clusters at higher mole% M203.
- Type
- Research Article
- Information
- Copyright
- Copyright © Materials Research Society 1989