کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1476459 1510146 2007 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Complex impedance spectroscopy study of a liquid-phase-sintered α-SiC ceramic
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Complex impedance spectroscopy study of a liquid-phase-sintered α-SiC ceramic
چکیده انگلیسی

The electrical response of a liquid-phase-sintered (LPS) α-SiC with 10 wt.% Y3Al5O12 (YAG) additives was studied from near-ambient temperature up to 800 °C by complex impedance spectroscopy. The electrical conductivity of this LPS SiC ceramic was found to increase with increasing temperature, which was attributed to the semiconductor nature of the SiC grains. It was concluded that the contribution of the SiC grains to the electrical conductivity of the LPS SiC ceramic at moderate temperatures (<450 °C) is a somewhat greater than that of the YAG phase. In contrast, at higher temperatures the SiC grains control the electrical conductivity of the LPS SiC ceramic. It was also found that there are two activation energies for the electrical conduction process of the α-SiC grains. These are 0.19 eV at temperatures lower than ∼400 °C and 2.96 eV at temperatures higher than ∼500 °C. The existence of two temperature-dependence conduction regimes reflects the core–shell substructure that develops within the SiC grains during the liquid-phase sintering, where the core is pure SiC (intrinsic semiconductor) and the shell is mainly Al-doped SiC (extrinsic semiconductor).

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of the European Ceramic Society - Volume 27, Issues 13–15, 2007, Pages 3935–3939
نویسندگان
, , , ,