Low temperature sintered of Ba3MgNb2O9 ceramics with high quality factor via B-site oxide precursor method.

B-site oxide precursor method was utilized to synthesize Ba₃MgNb₂O₉ ceramics. The effects of sintering temperature on phase composition of Ba₃MgNb₂O₉ ceramics was evaluated by the X-ray diffraction. Experimental results indicated that all prepared Ba₃MgNb₂O₉ ceramics exhibited 1:2 ordered hexagonal structure. The second phase Ba₅Nb₄O₁₅ can emerge in all ceramics due to the decrease of activation energy of reaction, leading to the splitting of E_g(O) vibration mode in the Raman spectra. In addition, lattice parameters of 1:2 ordered phase were obtained from the refinement of XRD patterns. The maximum value of c/a ratio occurred at 1475 °C, meanwhile the ceramics showed the highest 1:2 ordered degree and excellent Q × f. It was also found that the uniform grain-size distribution of Ba₃MgNb₂O₉ powder were important factors for preparing dense Ba₃MgNb₂O₉ ceramics. Moreover, B-site oxide precursor method can not only effectively lower the densification temperature from 1650 to 1475 °C, but also increase the quality factor (Q × f) by about 90.8%, i.e., from 55,277 to 105,467 GHz. [ABSTRACT FROM AUTHOR]