The electrode impedance spectrum of the oxide produced on a Zr-1%Nb surface in an aqueous solution at 290°C is analysed as a function of temperature between 20°C and 290°C. The portion of the spectrum, relevant to the oxide, is treated in terms of a parallel CPEk∥Rox equivalent circuit (CPE denoting constant phase element, Rox ohmic resistor). Considering also the effect of temperature CPE is understood as a dispersive resistance described by the continuous time random walk theory of Scher and Lax. Distinction is made between the kinetics of oxide growth and of non-Faraday charge transport, the time constant of the latter being obtained directly from impedance data.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry