Influence of both milling conditions and lithium salt addition on the sinterability of Ba(Zn1/3Ta2/3)O3

The complex perovskite oxide Ba(Zn1/3Ta2/3)O3 (BZT) has been largely studied for its interesting dielectric properties. This material possesses a relatively high dielectric constant associated with very low losses at usual frequency applications. It can be used as hyperfrequency resonators or capacitors. Unfortunately, a high sintering temperature is required to achieve high-density materials (>1500 °C), which is too high for industrial applications. The development of base metal electrode multi layer ceramic capacitors (BME MLCC) requires a low sintering temperature to be co-sintered with non-noble metals such as Ni and Cu. The technological process has been investigated with respect to milling conditions and calcination parameters to optimise each fabrication step. In addition, lithium salt (Li2CO3, LiF, BaLiF3 and LiNO3) additions have been tested to lower the sintering temperature. The BZT sintering temperature can be lowered to 200 °C when 15 mol% of LiF is added without modifying permittivity and loss factors at 1 MHz. Each sample was characterised in terms of density, microstructure and dielectric properties.