a1 Ceramics and Composites Laboratory, Department of Engineering Materials, The University of Sheffield, Sheffield, S1 3JD United Kingdom
a2 Center for Dielectric Studies, Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802
a3 Ceramics and Composites Laboratory, Department of Engineering Materials, The University of Sheffield, Sheffield, S1 3JD United Kingdom
BaCo1/3Nb2/3O3 ceramics, with a high density and a similar, high degree of 1:2 B-site cation ordering, exhibit very different quality factors, Q. The ceramics exhibit p-type behavior with higher conductivity and lower Q for samples processed in O2 as compared with those processed in air. It is proposed that unavoidable Co loss during high-temperature ceramic processing leads to p-type doping that must be compensated by oxygen vacancies to impede hole formation. The composition exhibiting only intrinsic conduction and optimized Q is not achieved with processing in atmospheric oxygen due to filling of oxygen vacancies and hole formation during cooling.
(Received November 19 2009)
(Accepted March 08 2010)