The ac conductivity of CaCu₃Ti₄O₁₂ ceramics associated with electrical charge carrier motion (ions or vacancies) was investigated as a function of frequency at different temperatures. The long range migration of charge carriers within the ceramic is restricted by two kinds of insulating barriers, namely, grain boundaries and domain boundaries. The potential barriers associated with these boundaries lead to two anomalies in conductivity response and three frequency-dependent contributions to conductivity: long range diffusion of carriers, carrier migration localized within grains, and carrier migration localized within domains.
W. Li and R. W. Schwartz, "AC Conductivity Relaxation Processes in CaCu₃Ti₄O₁₂ Ceramics: Grain Boundary and Domain Boundary Effects," Applied Physics Letters, American Institute of Physics (AIP), Dec 2006.
The definitive version is available at http://dx.doi.org/10.1063/1.2405382
Materials Science and Engineering
United States. Office of Naval Research
Keywords and Phrases
Calcium compounds; Domains; Electrical conductivity; Vacancies (crystal); Ceramics; Copper compounds; Dielectric relaxation; Grain boundaries
Article - Journal
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