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

摘要

Bearing in mind the excellent dielectric properties at high frequency of some niobates like ZnNb_2O_6, Zn_3Nb_2O_8, BaNb_2O_6, Ba_5Nb_4O_(15) (epsilon_r approx 20-45, tan delta < 10 X 10~(-4) and rho_i > 10~(10) OMEGA 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 deg 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 deg C. This result makes this formulation suitable for silver based passive components devices manufacturing.