Investigation of some niobate-based dielectrics in view of base metal co-sintering

Bearing in mind the excellent dielectric properties at high frequency of some niobates like ZnNb2O6, Zn3Nb2O8, BaNb2O6, Ba5Nb4O15 (ɛr ∼20–45, tan δ < 10 × 10−4 and ρi > 1010 Ω cm), synthesis, sintering and properties of these oxides are reported. The lowering of their sintering temperature has been investigated for these four ceramics using sintering aids. Using appropriate additive, it is possible to densify these ceramics at a temperature for which base metal electrodes, e.g. Cu and Ag can be employed. Two formulations were found to be sinterable at 1000 °C (lower than the copper melting point) whereas a third formulation is co-sinterable with silver electrodes. For this later, the dielectric properties are globally maintained in comparison with the pure compound sintered at 1200 °C. This result makes this formulation suitable for silver based passive components devices manufacturing.