Premium
Defect Chemistry of BaTiO 3 with Additions of CaTiO 3
Author(s) -
ZHANG XIAO WEN,
HAN YOUNG HO,
LAL MISRI,
SMYTH DONALD M.
Publication year - 1987
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1987.tb04937.x
Subject(s) - conductivity , enthalpy , impurity , electrical resistivity and conductivity , oxygen , analytical chemistry (journal) , chemistry , acceptor , mineralogy , materials science , inorganic chemistry , thermodynamics , condensed matter physics , physics , organic chemistry , electrical engineering , engineering , chromatography
The substitution of up to 5% Ca 2+ for Ba 2+ in BaTiO 3 results in a shift in the oxygen pressure dependence of the equilibrium electrical conductivity that is in the same direction as that caused by addition of acceptor impurities such as Al 3+ or Ca 2+ substituted for Ti 4+ . In contrast to the latter effect, however, the shape of the conductivity plot is not changed, the conductivity value at the conductivity minimum is not affected, and the amount of the shift increases with decreasing temperature of measurement. It is shown that the shift is primarily due to an increase in the enthalpy of reduction and a decrease in the enthalpy of oxidation as increasing amounts of Ba 2+ are replaced by Ca 2+ .