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Electric and Dielectric Properties of Nb‐Doped CaCu 3 Ti 4 O 12 Ceramics
Author(s) -
Hong SeongHyeon,
Kim DohYeon,
Park HyunMin,
Kim YoungMin
Publication year - 2007
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.1551-2916.2007.01709.x
Subject(s) - materials science , dielectric , grain boundary , sintering , electrical resistivity and conductivity , ceramic , grain size , doping , analytical chemistry (journal) , mineralogy , phase boundary , barrier layer , high κ dielectric , composite material , microstructure , phase (matter) , layer (electronics) , optoelectronics , electrical engineering , chemistry , organic chemistry , chromatography , engineering
Pure and Nb‐substituted CaCu 3 Ti 4− x Nb x O 12+ x /2 (CCTO, x =0, 0.02, 0.1, 0.2, 0.4) ceramics were prepared by a conventional solid‐state sintering, and their electric and dielectric properties were investigated using an impedance analyzer. A single‐phase CCTO was obtained up to x =0.2 Nb substitution and the lattice parameter increased with Nb substitution concentration. While the grain size decreased with Nb substitution, the resistivity of the grain boundary decreased. The dielectric constant increased with Nb substitution, and the highest value of ∼420 000 was observed in the x =0.2 Nb‐substituted specimen at 10 kHz. The obtained electric and dielectric properties in Nb‐substituted CCTO were discussed in terms of the internal barrier layer capacitor model, particularly focusing on a ratio of thickness of the grain boundary region to grain size.