کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10626663 989695 2005 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Charge compensation mechanism in yttria-doped barium titanate
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Charge compensation mechanism in yttria-doped barium titanate
چکیده انگلیسی
A commercial TiO2-excess BaTiO3 powder doped with Y2O3 has been pressureless-sintered using conventional tube furnace and CO2-laser, and the room-temperature electrical conductivity determined. Grain-growth inhibition is found to occur at ∼0.40 mol% Y2O3 where the refined microstructure of an average grain size of ∼1 μm is obtained from sintering at 1215 °C. The principal charge compensation mechanism in Y2O3-doped BaTiO3 depending upon temperature can be divided into three characteristic regimes. The mechanism is predominantly of the cation vacancy compensation at temperatures <1210 °C, a mixed mode at 1210-1500 °C, and the electron compensation when sintering temperature exceeds 1500 °C. Sintering using the CO2-laser has enabled the retention of the high temperature defect equilibrium which renders the room-temperature conductivity of ∼10−2 (Ω mm)−1 to the ceramics. The sintering of Y2O3-doped BaTiO3 ceramics is improved since densification is enhanced by faster barium diffusion via the extrinsic cation vacancy and coarsening suppressed by high Y2O3-content due to reduced grain-boundary mobility by second-phase (Y2Ti2O7) pinning.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ceramics International - Volume 31, Issue 7, 2005, Pages 989-997
نویسندگان
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