The microwave dielectric properties of the low-temperature firing BaZnP2O7 ceramics with Co2+ substitution

In this study, the microwave dielectric properties of Co 2+ -substituted BaZnP 2 O 7 ceramics prepared through conventional solid-state synthesis were investigated. X-ray diffraction, Rietveld refinement, energy-dispersive spectroscopy, and Raman spectroscopy all indicated that BaZn 1− x Co x P 2 O 7 ceramics sintered at 875°C were composed of a single phase. The lattice strain and crystallite size were estimated using Williamson–Hall (W–H) method. Both the scanning electron microscopy images and density measurements showed that Co 2+ ions had an effect on the grain growth and densification of ceramics. The microwave dielectric properties were influenced by the intrinsic and extrinsic factors that varied with the increase of x value. An optimal performance ( ε r = 7.62, Q × f = 600 45 GHz, and τ f = −74 ppm/°C) was achieved at x = .01. The porosity and relative density played a significant role in the dielectric constant ε r : the denser the ceramic structure, the larger the dielectric constant. The Q × f and τ f values were negatively correlated with the full width at half maximum of the Raman vibrational peak at approximately 1049 cm −1 . Moreover, the Q × f value was improved compared to that of the undoped BaZnP 2 O 7 ceramics. Therefore, cobalt ion substitution is an effective strategy to enhance the performance of microwave dielectric ceramics.