Proton conductivity of Ca-doped Tb2O3

The electrical conductivity of 2 mol% CaO-doped Tb2O3 has been characterized as a function of the oxygen pressure and water vapor pressure from 300 to 1200 deg C with two- and four-point electrode setups. EMF-measurements under reducing conditions have, furthermore, been applied to establish the con...

Full description

Saved in:
Bibliographic Details
Published in:Solid state ionics 2005-12, Vol.176 (39-40), p.2957-2961
Main Authors: HAUGSRUD, R, LARRING, Y, NORBY, T
Format: Article
Language:English
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The electrical conductivity of 2 mol% CaO-doped Tb2O3 has been characterized as a function of the oxygen pressure and water vapor pressure from 300 to 1200 deg C with two- and four-point electrode setups. EMF-measurements under reducing conditions have, furthermore, been applied to establish the contribution from the different charge carriers. Tb2O3 is a p-type semiconductor. Protons are the major ionic charge carrier under reducing conditions constituting 2-35% of the total conductivity, increasing with decreasing temperature. The conductivity under wet hydrogen has been modeled assuming that protons and oxygen vacancies compensate the acceptor (Ca). On this basis, the enthalpy and entropy of hydration, and the enthalpy and pre-exponential of proton mobility have been determined. These parameters are compared to corresponding data for the other rare-earth sesquioxides.
ISSN:0167-2738
DOI:10.1016/j.ssi.2005.09.030