Conductivity measurements on thoria and thoria--yttria solid solutions at high oxygen pressures

Journal Article · Mon Jan 01 04:00:00 EST 1973 · High Temp. - High Pressures, v. 5, no. 3, pp. 265-271

OSTI ID:4346385

Iqbal, M; Baker, E H

The total ac conductivities of thoria and thoria- yttria solid solutions were measured at oxygen pressures in the range 10/sup -7/ to 500 atm. and at temperatures in the range 800 to 1100 deg C. At the lowest pressures the conductivity is found to be virtually independent of pressure, indicative of an ionic conduction mechanism, but with the pressure increasing above ~-10/sup -4/ atm, a p-type conductivity which is pressure dependent is observed. At the highest oxygen pressures, the conductivity is found to be approximately proportional to the square root of oxygen fugacity. It is suggested that for the thoria-- yttria solid solutions, the p-type conduction results mainly from the filling of anion vacancies, but for thoria itself, the p-type conduction is probably determined mainly by generation of cation vacancies. Activation energies for the hole conduction are similar to those for the ionic conduction. (auth)

• Research Organization: Imperial Coll. of Science and Tech., London
• NSA Number: NSA-29-021327
• OSTI ID: 4346385
• Journal Information: High Temp. - High Pressures, v. 5, no. 3, pp. 265-271, Journal Name: High Temp. - High Pressures, v. 5, no. 3, pp. 265-271; ISSN HTHPA
• Country of Publication: United Kingdom
• Language: English

Related Subjects

*THORIUM OXIDES-- ELECTRIC CONDUCTIVITY
*YTTRIUM OXIDES-- ELECTRIC CONDUCTIVITY
EXPANSION
HIGH PRESSURE
HIGH TEMPERATURE
HIGH VACUUM
IONIC CONDUCTIVITY
LOW PRESSURE
MEDIUM PRESSURE
MEDIUM VACUUM
N50130* --Metals
Ceramics
& Other Materials--Ceramics & Cermets--Properties
Structure & Phase Studies
OXYGEN
P-TYPE CONDUCTORS
PRESSURE DEPENDENCE
SOLID SOLUTIONS
VACANCIES
VERY HIGH TEMPERATURE