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Ce 2 [Zr 1−x (Ca 1/3 Sb 2/3) x ] 3 (MoO 4) 9 (CZ 1−x (CS) x M) (x = 0.02–0.10) ceramics were prepared by the conventional solid-state reaction method. The correlations between the chemical bond parameters and microwave dielectric properties were calculated and analyzed by using the Phillips–Van Vechten–Levine (P–V–L) theory. Phase composition and microstructures were evaluated by scanning electron microscopy and X-ray diffraction patterns. Lattice parameters were obtained by Rietveld refinements based on XRD data. Excellent properties for Ce 2 [Zr 0.96 (Ca 1/3 Sb 2/3) 0.04 ] 3 (MoO 4) 9 ceramic sintered at 775 °C: ε r = 10.68, Q × f = 85,336 GHz and τ f = −7.58 ppm/°C were achieved. [ABSTRACT FROM AUTHOR]

Ceramics with composition of Pr 2 (Zr 1−x Ti x) 3 (MoO 4) 9 (0.02 ≤ x ≤ 0.10) were fabricated by classic solid-phase method. X-ray diffractometer (XRD), Scanning electron microscope (SEM), Raman spectra, FT-IR spectrometer and Agilent vector network analyzer were used to investigate the composition of phase, microscopy, lattice vibration, internal dielectric responding and dielectric properties, respectively. XRD indicates the Pr 2 (Zr 1−x Ti x) 3 (MoO 4) 9 (0.02 ≤ x ≤ 0.10) ceramics own trigonal-type crystal structure and R-3c space group and the SEM patterns confirms the optimal sintering temperature is 800 °C. Simultaneously, the ceramic reached the optimal microwave dielectric properties with ε r = 10.8, Q×f = 81,539 GHz and τ f = −14.2 ppm/°C at 800 °C for x = 0.10. By means of the theory of complex crystals chemical bonds (P-V-L theory), the connections with crystal structure and microwave dielectric properties were deeply discussed. Due to the relatively low fired temperature and superior dielectric properties, there is an expect for Pr 2 (Zr 0.90 Ti 0.10) 3 (MoO 4) 9 ceramic to apply in low temperature cofired ceramic (LTCC). [Display omitted] • Rietveld refinement was used to obtain the cell parameters. • The effects of substitution of Zr4+ by Ti4+ on Pr 2 Zr 3 (MoO 4) 9 ceramics was explored based on the P-V-L theory. • Q·f value has been improved by more than 130% in Pr 2 (Zr 0.90 Ti 0.10) 3 (MoO 4) 9 ceramics. • Optimum microwave dielectric properties (ε r = 10.8, Q×f = 81,539 GHz and τ f = −14.2 ppm/°C) were obtained at 800 °C. [ABSTRACT FROM AUTHOR]

• Low-sintered Nd 2 (Zr 1−x Sn x) 3 (MoO 4) 9 ceramics were prepared successfully. • Rietveld refinement was used to obtain the lattice parameters. • Relationships between intrinsic factors and dielectric properties were investigated. • Performance of Nd 2 Zr 3 (MoO 4) 9 ceramics was improved by the doping of Sn4+. [Display omitted] In this work, Nd 2 (Zr 1- x Sn x) 3 (MoO 4) 9 (0.02 ≤ x ≤ 0.1) (NZSM) ceramics were successfully obtained through conventional solid-state route. Phase analysis, microstructure, and properties were investigated scientifically by XRD, SEM, and network analyzer, respectively. XRD results revealed that all samples with different substitution amounts of Sn4+ formed the pure phase with R-3c space group. The permittivity was related to the polarizability and the bond of Zr2-O5, the bond of Nd-O2 possessed a positive influence on Q×f. The reduced octahedral distortion and increased bond energy made the temperature coefficient more stable. Infrared reflection spectrum results showed that the permittivity was mainly caused by the absorption of phonon oscillation. The optimum properties (ε r = 10.34, Q×f = 74,795 GHz, τ f = −13.55 ppm/°C) were obtained when x = 0.02 sintered at 750 °C. [ABSTRACT FROM AUTHOR]

• Low-sintered Ce 2 [Zr 1−x (Zn 1/3 Ta 2/3) x ] 3 (MoO 4) 9 ceramics were prepared successfully. • Rietveld refinement was used to obtain the lattice parameters. • Relationships between intrinsic factors and dielectric properties were investigated. • Performance of Ce 2 Zr 3 (MoO 4) 9 ceramics was improved by the doping of (Zn 1/3 Ta 2/3)4+. [Display omitted] Ce 2 [Zr 1−x (Zn 1/3 Ta 2/3) x ] 3 (MoO 4) 9 compounds were successfully prepared and researched. Phase analysis, microstructures and properties were studied scientifically by XRD, SEM and network analyzer, respectively. Rietveld refinement of all compositions confirmed that a single phase in trigonal crystal structure with R -3 c space group was obtained. Infrared reflection spectrum results showed the permittivity was related to the absorption of phonon oscillation. SEM images revealed that the average grain size decreased with the increase of (Zn 1/3 Ta 2/3)4+. Microwave dielectric properties analysis indicated that the permittivity was related to the polarizability, Mo-O made a more significant contribution to the Q × f , and τ f was related to the octahedral distortion. The optimum properties (ε r = 10.77, Q × f = 74,682 GHz, τ f = −12.84 ppm/°C) were obtained when x = 0.04 sintered at 750 °C. [ABSTRACT FROM AUTHOR]