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.