Crystal Structure, Infrared Spectra, and Microwave Dielectric Properties of Temperature-Stable Zircon-Type (Y,Bi)VO(4) Solid-Solution Ceramics

[Image: see text] A series of (Bi(1–x)Y(x))VO(4) (0.4 ≤ x ≤ 1.0) ceramics were synthesized using the traditional solid-state reaction method. In the composition range of 0.4 ≤ x ≤ 1.0, a zircon-type solid solution was formed between 900 and 1550 °C. Combined with our previous work (scheelite monoclinic and zircon-type phases coexist in the range of x < 0.40), a pseudobinary phase diagram of BiVO(4)–YVO(4) is presented. As x decreased from 1.0 to 0.40, the microwave permittivity (ε(r)) of (Bi(1–x)Y(x))VO(4) ceramics increased linearly from 11.03 to 30.9, coincident with an increase in the temperature coefficient of resonant frequency (TCF) from −61.3 to +103 ppm/°C. Excellent microwave dielectric properties were obtained for (Bi(0.3)Y(0.7))VO(4) sintered at 1025 °C and (Bi(0.2)Y(0.8))VO(4) sintered at 1075 °C with ε(r) ∼ 19.35, microwave quality factor (Qf) ∼ 25 760 GHz, and TCF ∼ +17.8 ppm/°C and ε(r) ∼ 16.3, Qf ∼ 31 100 GHz, and TCF ∼ −11.9 ppm/°C, respectively. Raman spectra, Shannon’s additive rule, a classical oscillator model, and far-infrared spectra were employed to study the structure–property relations in detail. All evidence supported the premise that Bi-based vibrations dominate the dielectric permittivity in the microwave region.