Combustion synthesis and characterization of nanocrystalline Ba(Mg1/3Nb2/3)O3 powders

Nanocrystalline Ba(Mg1/3Nb2/3)O3 (BMN) powders were successfully synthesized through a modified combustion synthesis method by using Ba(NO3)2, Mg(NO3)3·6H2O and Nb2O5 as starting materials. Gel precursor and calcined powders were characterized by thermogravimetric (TG), differential scanning calorimetry (DSC), X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). The results demonstrate that pure perovskite Ba(Mg1/3Nb2/3)O3 powder formed at 800 °C for 2 h. And the crystallite size was about 40 nm. The specimen sintered at 1550 °C for 12 h shows 96.3% of the theoretical density and gave the excellent microwave dielectric properties: ɛr = 31.3 and Qf = 71,800 GHz.