Apparent non-monotonic electrical conductivity relaxation of 1 % Gd-doped ceria
Year: 2025
Type: article
Abstract: Steady-state and transient electrical conductivities of 1 % Gd-substituted ceria have been characterized from 550 to 800 °C under oxidizing conditions. The temperature and oxygen pressure dependencies of the steady-state conductivity resemble those of pristine ceria, with predominant n-type conductivity and some contribution of p-type conductivity under the most oxidizing conditions. Depending on temperature and oxygen partial pressure, the relaxation of the conductivity follows one-fold monotonic, two-fold monotonic, or non-monotonic behavior, despite the predominance of two charge carriers in the bulk material. Possible explanations for this peculiar phenomenon are discussed based on surface-exchange-limited oxygen exchange. • 1 % Gd doping is used to probe and extrapolate the oxygen exchange kinetics of nominally pristine ceria. • Steady-state conductivity of 1GDC revels p-type conductivity under atmospheric conditions. • ECR measurements show both monotonic and non-monotonic relaxation behaviors in 1GDC. • Monotonic relaxation transitions to non-monotonic behavior with increasing temperature and decreasing pO 2 . • Reestablishment of the space charge layer is proposed to explain the relaxation behavior.
Source: Solid State Ionics
Authors: Yizhou Shen, Reidar Haugsrud
Institution: University of Oslo
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,560
Funder: Norges Forskningsråd
Award: G3465688948
OpenAlex ID: W4414274184