Mixture behavior and microwave dielectric properties of (1 − x)Ca2P2O7-xTiO2

(1 − x)β-Ca2P2O7-xTiO2 were prepared by solid-state reaction. The mixture behavior and microwave dielectric properties were investigated using X-ray powder diffraction and a network analyzer, respectively. X-ray powder diffraction patterns showed that β-Ca2P2O7 and TiO2 existed in a mixture form, which was also confirmed by SEM analysis. It was shown that TiO2, which has positive temperature coefficient of the resonant frequency (τf), compensated the negative τf of β-Ca2P2O7 (−53 ppm/°C) through mixture formation. The variation of dielectric properties with a function of TiO2 contents could be explained using mixture rule. In the 0.3 < x < 0.4 regions, τf value could be successfully reduced almost zero. In particular, at x = 0.3, good microwave dielectric properties was obtained: Q × f = 44,000, ɛr = 10.9, and τf = −11 ppm/°C.