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The microwave dielectric characteristics and mixture behavior of (1 − x)CaWO 4 -xTiO 2 ceramics prepared with conventional solid-state route were studied using a network analyzer and X-ray power diffraction, respectively. The CaWO 4 compound had good properties (low permittivity and high quality factor) for microwave applications, but it had a high negative temperature coefficient of resonant frequency (τ f = −53). Hence, in order to tune the dielectric properties, (1 − x)CaWO 4 -xTiO 2 were prepared for different values of x. X-ray powder diffraction and SEM analysis revealed that CaWO 4 and TiO 2 coexisted as a mixture. The mixture formation and dielectric properties could be explained by mixture rule. In particular, at x = 2.6, good microwave dielectric properties were obtained: Qf = 27,000, ε r = 17.48, and τ f = ∼0 ppm/ • C.

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Glasses in the ZnO-B 2 O 3 -MO 3 (M = W, Mo) ternary were examined as potential replacements to PbO-B 2 O 3 -SiO 2 -ZnO glass frits with the low firing temperature (500-600 • C) for the dielectric layer of a plasma display panels (PDPs). Glasses were melted in air at 950-1150 • C in a narrow region of the ternary using standard reagent grade materials. The glasses were evaluated for glass transition temperature (T g ), softening temperature (T d ), the coefficient of thermal expansion (CTE), dielectric constant (ε r ), and optical property. The glass transition temperature of the glasses varied between 470 and 560 • C. The coefficient of thermal expansion and the dielectric constant of the glasses were in the range of 5-8 × 10 −6 / • C and 8-10, respectively. The addition of MO 3 to ZnO-B 2 O 3 binary could induce the expansion of glass forming region, the reduction of T g and the increase in the CTE and the dielectric constant of the glasses. Also, the effect of the addition of MO 3 to ZnO-B 2 O 3 binary on the transmittance in the visible-light region (350-700 nm) was investigated.

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