Effects of additives on the sintering temperature and dielectric properties of ZnTiO3 based ceramic

The effects of various additives, namely ZnO–B2O3–SiO2 (ZSB), B2O3 and B2O3 + LiF on the lowering of sintering temperature and dielectric properties of ZnTiO3 based ceramics were investigated. From the dilatometric studies, it was shown that the sintering temperature is significantly lowered owing to the addition of 15 mol.% of ZSB or of the addition of 15 mol.% of B2O3: ZSB added sample can be sintered at 950 °C and B2O3 added one at 1000 °C whereas pure compound hence can be sintered at 1100 °C. The most interesting result concerns the ZSB added sample sintered at 950 °C during 4 h which exhibits a density higher than 92% of the theoretical one, high dielectric constant (ɛr ≈ 25) and low dissipation factor (tan(δ) < 10−3) in the range −60 °C/160 °C at 1 MHz. The temperature coefficient of the dielectric constant is also reasonable (τɛ ≈ −150 ppm/°C) as well as the temperature coefficient of the resonant frequency (|τf| < 100 ppm/°C). This formulation should be consequently a suitable candidate for low-temperature co-fired ceramics (LTCCs).