کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1475902 991134 2010 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of packing fraction and bond valence on microwave dielectric properties of A2+B6+O4 (A2+: Ca, Pb, Ba; B6+: Mo, W) ceramics
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Effects of packing fraction and bond valence on microwave dielectric properties of A2+B6+O4 (A2+: Ca, Pb, Ba; B6+: Mo, W) ceramics
چکیده انگلیسی

Microwave dielectric properties of A2+B6+O4 (A2+: Ca, Pb, Ba; B6+: Mo, W) ceramics were investigated as a function of packing fraction and bond valence. For A2+B6+O4 specimens sintered at 800–1100 °C for 3 h, a single phase with a tetragonal scheelite structure was detected, and the theoretical density was higher than 93% throughout the composition. Although the ionic polarizability of Ba2+ ion was larger than that of Ca2+ ion, the dielectric constant (K) of BaB6+O4 showed a smaller value than that of CaB6+O4. These results could be attributed to changes of the packing fraction due to the effective ionic size. The Q·f value was largely dependent on the packing fraction, as well as the percentages of theoretical density. The temperature coefficients of the resonant frequencies (TCFs) of the specimens were affected by the bond valence of oxygen. The specimens of CaMoO4 sintered at 1000 °C for 3 h showed the K of 10.8, Q·f of 76,990 GHz and TCF of −22.8 ppm/°C, respectively.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of the European Ceramic Society - Volume 30, Issue 7, May 2010, Pages 1731–1736
نویسندگان
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