Crystal structure, chemical bond characteristics, infrared reflection spectrum, and microwave dielectric properties of Nd2(Zr1-xTix)3(MoO4)9 ceramics

Microwave dielectric ceramics (MWDCs) with low dielectric constant and low dielectric loss are desired in contemporary society, where the communication frequency is developing to high frequency (sub-6G). Herein, Nd-2(Zr1-xTix)(3)(MoO4)(9) (NZ(1-x)T(x)M, x = 0.02-0.10) ceramics were prepared through a solid-phase process. According to X-ray diffraction (XRD) patterns, the ceramics could form a pure crystal structure with the R (3) over barc (167) space group. The internal parameters affecting the properties of the ceramics were calculated and analyzed by employing Clausius-Mossotti relationship, Shannon's rule, and Phillips-van Vechten-Levine (P-V-L) theory. Furthermore, theoretical dielectric loss of the ceramics was measured and analyzed by a Fourier transform infrared (IR) radiation spectrometer. Notably, when x = 0.08 and sintered at 700 degrees C, optimal microwave dielectric properties of the ceramics were obtained, including a dielectric constant (epsilon(r)) = 10.94, Q center dot f = 82,525 GHz (at 9.62 GHz), and near-zero resonant frequency temperature coefficient (tau(f)) = -12.99 ppm/degrees C. This study not only obtained an MWDC with excellent properties but also deeply analyzed the effects of Ti4+ on the microwave dielectric properties and chemical bond characteristics of Nd2Zr3(MoO4)(9) (NZM), which laid a solid foundation for the development of rare-earth molybdate MWDC system.

Automated summary

In this study, microwave dielectric ceramics with low dielectric constant and low dielectric loss were prepared and their properties were analyzed. The effects of internal parameters on the ceramics' properties were calculated and analyzed. Theoretical dielectric loss of the ceramics was measured and optimal microwave dielectric properties were obtained for a specific composition and sintering temperature. This study not only obtained MWDCs with excellent properties but also analyzed the effects of Ti4+ on the microwave dielectric properties and chemical bond characteristics.