Microstructure, bonding characteristics, far-infrared spectra and microwave dielectric properties of co-substituted Ce2[(Zr1-x(Zn1/3Sb2/3)x]3(MoO4)9 ceramics

Abstract

In this contribution, Ce2[(Zr1-x(Zn1/3Sb2/3)x]3(MoO4)9 (CZ1−x(ZS)x) (0 ≤ x ≤ 0.1) ceramics were fabricated using the solid-state reaction method, and the phase composition of the synthesized ceramics was analyzed via XRD and Rietveld refinement. The outcomes revealed that the ceramics, characterized by different x values, constituted a solitary phase with an R-3C space group, and the cell volume demonstrated a decrease with an increase in x value. The examination of the ceramics microwave dielectric characteristics using P–V−L theory reveals that the fi(Ce–O(6)) bond was found to be related to εr, while Q × f was influenced by the average grain size and Uave.(Mo–O), and Eave.(Mo–O) and αave.(Mo–O) were related to the τf value. The optimal properties were achieved at 750 °C (x = 0.02), resulting in εr = 10.08, Q × f = 100,954 GHz, τf = −12.46 ppm/°C. The infrared reflection spectrum analysis revealed that the primary polarization contribution was due to the dielectric response of intrinsic phonons. Additionally, the effects of three different complex ions (Zn1/2Sb2/3)4+, (Zn1/2Ta2/3)4+, and (Zn1/2Nb2/3)4+ doping on the properties of Ce2Zr3(MoO4)9 ceramics were investigated using SEM, packing fraction, and chemical bond analysis. The results showed that (Zn1/2Sb2/3)4+ doping was effective in improving the grain size and apparent density of Ce2Zr3(MoO4)9 ceramics, and the high packing fraction and U(Mo–O) were found to be the primary intrinsic factors for the optimal properties.