Temperature-stable dielectrics based on Cu-doped Bi2Mg2/3Nb4/3O7 pyrochlore ceramics for LTCC

Temperature-stable dielectrics based on Cu-doped Bi2Mg2/3Nb4/3O7 pyrochlore ceramics were prepared by conventional solid-state reaction. Microstructure analysis indicates that all of the specimen maintain the cubic pyrochlore phase, a fluorite-like phase of Bi3NbO7 and a Bi5Nb3O15 formed for Cu doping. The dielectric constant is dominated by densification of samples and secondary phases, while the dielectric loss is related by the secondary phases, grain boundaries, and leakage current characteristics. The (1-x)BMN - xCuO(x = 0.1 mol%) ceramic sintered at 925 °C shows excellent dielectric properties with dielectric constant of ~184.06, dielectric loss of ~0.0017 and near zero τε (−20 ppm/°C) is obtained at sintering temperature of 925 °C, which could be a promising candidate for LTCC.