Synthesis and Characterization of a New Sillenite Compound—Bi12(B0.5P0.5)O20

A new sillenite compound, Bi₁₂(B_0.5P_0.5)O₂₀, was synthesized using a solid-state reaction method. The stoichiometry was confirmed by XRD analyses, microstructural investigations, and quantitative elemental analysis. An investigation of the dielectric properties at frequencies from 100 Hz to 1 MHz revealed a broad, highly frequency-dispersive, relaxor-like dielectric anomaly, which appeared in the temperature range of −80°–100°C. The permittivity, Q × f value, and temperature coefficient of the resonant frequency, measured at ∼5.5 GHz, were determined to be 37.4, 850 GHz, and −19 ppm/K, respectively.