Phase composition, crystal structure, infrared reflectivity and microwave dielectric properties of temperature stable composite ceramics (scheelite and zircon-type) in BiVO₄-YVO₄ system

(1 - x)BiVO₄-xYVO₄ (x ≤ 0.65) ceramics were prepared using the solid state reaction method. X-ray diffraction, Raman spectra and scanning electron microscopy techniques were employed to study the phase composition and crystal structure. The ceramic samples were composed of both monoclinic scheelite and tetragonal zircon-type phases. The best microwave dielectric properties, with a permittivity ∼45, a Qf value 14000 GHz and a temperature coefficient of resonant frequency (TCF) +10 ppm°C^-1, were obtained in the 0.81BiVO₄-0.19YVO₄ ceramic sintered at 870°C for 2 h. Far-infrared spectra study showed that Bi-O oscillations dominate microwave dielectric polarizations in the (1 - x)BiVO₄-xYVO₄ ceramics. The (1 - x)BiVO₄-xYVO₄ ceramics might be potential candidates for microwave devices application and low temperature co-fired ceramic technology (LTCC).