Crystal structure and optimised microwave dielectric properties of Ce2(Zr1-xTix)3(MoO4)9 solid solutions

Abstract Ce2(Zr1-xTix)3(MoO4)9 (CZ1-xTxM) (x = 0.02–0.10) solid solutions were prepared via solid-state reaction method. The effects of Ti4+ ions substituting for Zr4+ on sintering behavior, structure and microwave dielectric properties of Ce2Zr3(MoO4)9 ceramics were investigated. X-ray diffraction (XRD) patterns combined with Rietveld refinements results confirmed that all compounds crystallized in a trigonal cell (R-3c). The Q·f values of the as-prepared samples were explained by the packing fraction and average grain size. Dielectric polarizability played a significant role in affecting the permittivity, and the τf values were associated with the bond valence of Zr-site. What's more, far-infrared reflectivity spectra were also used to explore the intrinsic dielectric properties of Ce2(Zr1-xTix)3(MoO4)9 (x = 0.08) ceramics. Typically, the desirable microwave dielectric properties of Ce2(Zr1-xTix)3(MoO4)9 ceramics were achieved in x = 0.08 when sintered at 775 °C for 6 h: er = 11.28, Q·f = 84,200 GHz and τf = −7.86 ppm/°C.