Low‐Temperature Sinterable (1− x ) Ba 3 ( VO 4 ) 2 – x LiMg 0.9 Zn 0.1 PO 4 Microwave Dielectric Ceramics

The novel low‐temperature sinterable (1 − x ) Ba 3 ( VO 4 ) 2 – x LiMg 0.9 Zn 0.1 PO 4 microwave dielectric ceramics were prepared by cofiring the mixtures of pure‐phase Ba 3 ( VO 4 ) 2 and LiMg 0.9 Zn 0.1 PO 4 . The phase structure and grain morphology of the ceramics were evaluated using X ‐ray diffraction, Raman spectra, and scanning electron microscopy. The results indicated that Ba 3 ( VO 4 ) 2 and LiMg 0.9 Zn 0.1 PO 4 phases can well coexist in the sintered body. Nevertheless, a small amount of LiZnPO 4 and some vanadate phases with low melting points were observed, which not only can influence the microwave dielectric properties of the ceramic but also can obviously improve the densification behavior at a relatively low sintering temperature. The near‐zero temperature coefficients of the resonant frequency (τ f ) could be achieved by adjusting the relative content of the two phases owing to their opposite τ f values and simultaneously a desirable quality factor Q × f value can be maintained. No chemical reaction between the matrix ceramic phase and Ag took place after sintering at 800°C for 4 h. The ceramics with 45 vol% LiMg 0.9 Zn 0.1 PO 4 can be well sintered at only 800°C and exhibit excellent microwave dielectric properties of ε r ~ 10, Q × f ~ 64 500 GHz, and τ f ~ −2.1 ppm/°C, thus showing a great potential as a low‐permittivity low‐temperature cofired microwave dielectric material.