Influence of CuO and BO on sintering and dielectric properties of tungsten bronze type microwave ceramics: a case study in BaNdTiO.

The effect of CuO and BO co-doping on the sintering behavior, microstructure and microwave dielectric properties of tungsten bronze type BaNdTiO (BNT) ceramics has been investigated by means of a traditional solid-state mixed oxide route. On the one hand, it was indicated that the mixture of CuO and BO is an effective sintering aid for BNT matrix compositions owing to the existence of a low-temperature eutectic reaction. On the other hand, it was found that the addition of CuO and BO has an obvious effect on microwave dielectric properties of BNT ceramics, depending on the amount of sintering aids, the sample density and microstructure. The liquid phases from sintering aids can promote densification, but simultaneously induce grain growth which tends to decrease the sintering driving force. BNT ceramics doped with 3 wt% CuO-BO mixture can be well sintered at 950°C for 4 h and still exhibit relatively good microwave dielectric properties. [ABSTRACT FROM AUTHOR]