Ba2BiSbO6: A novel microwave dielectric ceramic with monoclinic structure

A novel Ba 2 BiSbO 6 microwave dielectric ceramic was prepared via the traditional solid-state method, and the microwave dielectric properties of Ba 2 BiSbO 6 were investigated for the first time. The analysis of X-ray diffraction patterns indicated that the pure monoclinic Ba 2 BiSbO 6 phase could be formed in the temperature range of 950–1150 °C. Rietveld refinement results further confirmed that Ba 2 BiSbO 6 belonged to a monoclinic system with space group I2/m (12). Dense and homogeneous microstructures of Ba 2 BiSbO 6 ceramics sintered at 1100–1150 °C could be revealed from the scanning electric microscope. The bond ionicity, lattice energy and coefficient of the thermal expansion were initially calculated based on the complex chemical bond theory. The complex dielectric constant and loss were gained from the fitting data of far infrared spectra, which were in good agreement with the measured values. The optimum microwave dielectric properties of ε r  = 26.61, Q · f  = 13,764 GHz (at 5.95 GHz) and τ f  = −26.6 ppm/°C were achieved in Ba 2 BiSbO 6 ceramic sintered at 1100 °C.