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Microwave dielectric ceramics with intrinsic low sintering temperatures are potential candidates for low temperature co‐fired ceramics technology. In the present work, the (Li0.5Y0.5)MoO4 ceramic with tetragonal scheelite structures was selected to improve microwave dielectric properties of BiVO4 ceramics. As proved by X‐ray diffraction (XRD) results, scheelite structured solid‐solution ceramics were formed with x value ≤0.1 in the (Bi1−xLi0.5xY0.5x)(V1−xMox)O4. In situ XRD results further confirmed that the addition of (Li0.5Y0.5)MoO4 also lowered transition temperature from distorted monoclinic to tetragonal scheelite structure. When x value increased further, zircon phase was detected by XRD. Room and high‐temperature Raman spectra also supported the XRD results. Differences of thermal expansion coefficients of both monoclinic and tetragonal scheelite phases lead to an abnormality at phase transition temperature. Good microwave dielectric properties with permittivity above 70 and Qf (Q = quality factor = 1/dielectric loss and f = frequency) value above 8000 GHz were obtained in the (Bi1−xLi0.5xY0.5x)(V1−xMox)O4 solid‐solution ceramics with x value ≤0.1 sintered below 800°C. However, permittivity peak values at phase transition temperatures lead to large positive or negative temperature coefficient of resonant frequency, and this needs to be modified via composite technologies in the future. [ABSTRACT FROM AUTHOR]

In this study, the effects of BaCu(B 2 O 5) (BCB) additive on the low-temperature sintering behaviour, microstructure evolution and microwave dielectric properties of (Co 0.35 Zn 0.65)TiNb2O8 (CZTN) ceramics were systematically investigated by introducing the additive into the solid-state sintering process. Adding BCB successfully lowered CZTN ceramics' sintering temp from 1150 °C to 925 °C while preserving their superior microwave dielectric properties at the lower temperature. However, excessive BCB tends to disrupt the equilibrium between the native ixiolite and rutile phases within the ceramic matrix, thereby instigating a relative augmentation of the rutile phase, ultimately culminating in a positive shift in the temperature coefficient of the resonant frequency. Specific experimental data show that the CZTN ceramics prepared with a BCB content of 4 wt% exhibited good microwave dielectric properties after sintering at 925 ℃ for 4 h: relative dielectric constant (ε r) = 36.7, quality factor (Q × f) = 19,880 GHz, and τ f = +14.2 ppm/℃. In addition, the ceramic system showed good chemical compatibility when co-fired with Ag without significant elemental diffusion. This work reveals the specific role of BCB in enhancing low-temperature sintering of CZTN ceramics and pinpoints its ideal addition range, thereby offering crucial scientific insights and technical support for developing high-performance microwave dielectric ceramics for LTCC technology. [ABSTRACT FROM AUTHOR]