Microwave dielectric properties and sintering behaviors of scheelite compound CaMoO4

The microwave dielectric properties, sintering behaviors of scheelite compound CaMoO4 were investigated using dilatometry, X-ray diffraction, scanning electron microscopy and network analyzer. To improve the sintering property of CaMoO4, samples with different Ca/Mo ratio were prepared. The bulk densities of CaMo(x)O4 (for x = 1.02, 1.05, 1.08) samples were higher than those of pure CaMoo(4) over all temperature range. The well-sintered CaMo(X)O4 (for x = 1.02) sample with similar to 95.7% of the theoretical density shows Q x f value of 71,000 GHz and dielectric constant (epsilon(r)) = 10.3. The effects of liquid phase formation on sintering process and dielectric properties were discussed. Sample with hot-press sintering was also prepared in order to investigate dielectric properties of fully dense CaMoO4, which exhibited quality factor (Q x f), -55,000 GHz and dielectric constant (epsilon(r)) = 11.7. (c) 2005 Elsevier Ltd. All rights reserved.