Picture of scraped petri dish

Scrape below the surface of Strathprints...

The Strathprints institutional repository is a digital archive of University of Strathclyde research outputs. Explore world class Open Access research by researchers at Strathclyde, a leading technological university.

Explore

Reactive element effects on the ionic transport processes in Cr2O3 scales

Liu, H. and Stack, M.M. and Lyon, S.B. (1998) Reactive element effects on the ionic transport processes in Cr2O3 scales. Solid State Ionics, 109 (3-4). pp. 247-257. ISSN 0167-2738

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

A study of the ionic and electronic partial conductivity of Cr2O3 scales selectively grown on Ni-20%Cr alloy with and without yttria additions in hydrogen water vapour at 900 degrees C, was carried out by the asymmetry polarisation technique. The results revealed that there were two main regions for the temperature dependence of conductivity in the range 300-900 degrees C. Above 700 degrees C, the Cr2O3 scale was an intrinsic electronic conductor with a corresponding activation energy of 1.7 eV. Below 700 degrees C, the Cr2O3 scale was a mixed ionic and electronic conductor. The activation energy was 0.6eV for electronic conductivity and 0.3 eV for ionic conductivity. The ionic transference number decreased as the temperature or applied voltage increased. The data strongly suggest that the presence of the reactive element in the scale reduces the concentration of mobile species, thus lowering the ionic transport number.