Structure and conductivity of acceptor doped La2BaZnO5 and Nd2BaZnO5
Journal article, 2015
The effect of calcium substitution on the structure and electrical conductivity of Ln(2 - x)Ca(x)BaZnO(5 - delta), Ln = La and Nd, has been studied. Differing trends with respect to dependence of the unit cell volume were observed as a function of Ca substitution. For both series of materials the limit of Ca substitution was estimated to be x approximate to 0.2. The electrical conductivity was studied in the temperature range of 1000-350 degrees C using electrochemical impedance spectroscopy in argon and oxygen atmospheres and via isotherms between 400 and 1000 degrees C as function of oxygen pressure and the water vapour pressure. A marked increase in conductivity of approx. two orders of magnitude was explained by the presence of oxygen vacancies in the calcium doped samples. At pO(2) < 10(-12) atm atm the x = 0.15 materials are predominantly oxygen ion conductors, and La1.85Ca0.15BaZnO5 - delta displays a peak conductivity of 0.002 S cm(-1) at 1000 degrees C. The materials display a rise in conductivity in oxidizing conditions, indicating a significant p-type contribution.
SYSTEM
TRANSPORT
Mixed conductor
Physical
SOFC
PEROVSKITE
Impedance spectroscopy
ELECTROLYTES
ER
Oxide ion conductor
Chemistry
JOURNAL OF SOLID STATE CHEMISTRY
OXIDE-ION CONDUCTORS
Condensed Matter
Synthesis
1982
P176
HO
CHEL C
V42
Physics
DY
ND
Author
MD khairul Hoque
Chalmers, Chemistry and Chemical Engineering, Energy and Material
R. Haugsrud
University of Oslo
Christopher Knee
Chalmers, Chemistry and Chemical Engineering, Energy and Material
Solid State Ionics
0167-2738 (ISSN)
Vol. 272 160-165Subject Categories
Inorganic Chemistry
Driving Forces
Sustainable development
DOI
10.1016/j.ssi.2015.02.001