Low temperature sintering of ZnTiO3/TiO2 based dielectric with controlled temperature coefficient

Structure, microstructure and dielectric properties of ZnTiO3 and rutile TiO2 mixtures (ZnTiO3 + xTiO2 with x = 0, 0.02, 0.05, 0.1, 0.15 and 0.2) sintered using ZnO–B2O3 glass phase (5 wt.% added) as sintering aid have been investigated. For all compounds, the sintering temperature achieves 900 °C. The X-ray diffraction patterns indicate for x = 0.1 that the material is composed by three phases identified as ZnTiO3 hexagonal, TiO2 rutile and ZnO. The presence of ZnO is explained by the introduction of Ti into Zn site to form the (Zn1−xTix)TiO3+x solid solution in resulting the departure of ZnO from the ZnTiO3 structure. The ZnTiO3 + 0.15TiO2 composition sintered at 900 °C with glass addition exhibits attractive dielectrics properties (ɛr = 23, tan(δ) < 10−3 and a temperature coefficient of the dielectric constant near zero (τɛ = 0 ppm/°C)) at 1 MHz. It is also shown that the introduction of TiO2 allows to tune the temperature coefficient of the permittivity. All these properties lead this system compatible to manufacture silver based electrodes multilayer dielectrics devices.