D. Schonfeld et W. Laqua, DEFECT STRUCTURE AND SOLUBILITY RANGE OF GALLIUM-DOPED COBALT OXIDE, Berichte der Bunsengesellschaft fur Physikalische Chemie, 101(2), 1997, pp. 185-192
Citations number
18
Categorie Soggetti
Chemistry Physical
Journal title
Berichte der Bunsengesellschaft fur Physikalische Chemie
The electrical conductivity sigma of polycrystalline cobalt oxide dope
d with gallium oxide, Co(1-x)G(2x/3)O, was measured as a function of t
emperature (800-1400 degrees C), oxygen activity (10(-4)-0.21) and com
position x (0-0.125). The phase boundary of the solid solution as a fu
nction of temperature and oxygen activity was ascertained by a well-de
fined change of the slope in the sigma-T-Arrhenius plot. As a function
of Ga2O3-content, the electrical conductivity runs through more or le
ss distinct minima at all temperatures and oxygen activities. To expla
in these dependencies, a defect model was developed, which contains di
fferent defect associates and a 4:1-cluster. It emerges from a model i
n which associated holes contribute to the total conductivity as well
as free holes. Due to this fact different mobilities result for the re
spective holes.