화학공학소재연구정보센터
Journal of the American Ceramic Society, Vol.99, No.6, 2083-2088, 2016
Structure, Infrared Reflectivity and Microwave Dielectric Properties of (Na0.5La0.5)MoO4-(Na0.5Bi0.5)MoO4 Ceramics
A series of temperature-stable microwave dielectric c eramics, (1 - x)(Na0.5La0.5)MoO4-x(Na0.5Bi0.5)MoO4 (0.0 <= x <= 1.0) were prepared by using solid-state reaction. All specimens can be well sintered at temperature of 580 degrees C-680 degrees C. Sintering behavior, phase composition, microstructures, and microwave dielectric properties of the ceramics were investigated. X-ray diffraction results indicated that tetragonal scheelite solid solution was formed. Microwave dielectric properties showed that permittivity (epsilon(r)) and temperature coefficient of resonant frequency (tau(f)) were increased gradually, while quality factor (Q x f) values were decreased, at the x value was increased. The 0.45(Na0.5La0.5)MoO4-0.55(Na0.5Bi0.5)MoO4 ceramic sintered at 640 degrees C with a relative permittivity of 23.1, a Q x f values of 17 500 GHz (at 9 GHz) and a near zero tau(f) value of 0.28 ppm/degrees C. Far-infrared spectra (50-1000 cm(-1)) study showed that complex dielectric spectra were in good agreement with the measured microwave permittivity and dielectric losses.