Nonlinear electrical behavior and dielectric properties of (Ca, Ta)-doped TiO2 ceramics
2002; Elsevier BV; Volume: 335; Issue: 1-2 Linguagem: Inglês
10.1016/s0925-8388(01)01827-8
ISSN1873-4669
AutoresW.Y Wang, D.F Zhang, Tian-Bing Xu, X.F Li, Tianfu Zhou, X.L Chen,
Tópico(s)Ferroelectric and Piezoelectric Materials
ResumoTiO2 ceramics doped with 2.5 mol% Ta and different concentrations of Ca were obtained by sintering at 1300°C. As a varistor material, the nonlinear electrical behavior and dielectric properties of these ceramics were investigated. The ceramics have nonlinear coefficients a in the range 2.0–5.5 and high relative dielectric constants. The effects of Ca on the density, nonlinear electrical behavior, resistivity and dielectric properties of the Ta-doped TiO2 ceramics were also studied. The sample doped with 0.75 mol% Ca and 2.5 mol% Ta exhibits the highest nonlinear coefficient and a comparatively lower relative dielectric constant. By analogy to a grain-boundary defect model, the nonlinear electrical behavior of the TiO2 system is explained.
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