Crystal structure, infrared spectra, and microwave dielectric properties of low-firing Nd_2Zr_3(MoO_4)_9 ceramics prepared by reaction-sintering process

摘要

Low temperature-sintered ceramics Nd_2Zr_3(MoO_4)_9 were successfully prepared via reaction-sintering method. The sintering behavior, microwave dielectric properties, crystal structure, and microstructure were analyzed systematically. XRD and Rietveld refinement results revealed that all samples formed a pure trigonal structure phase with the space group of R-3c. Density determination showed that ceramics possessed the highest relative density when sintered at 800 °C for 6 h. SEM image further confirmed that ceramics possessed dense and homogeneous microstructure at the optimum sintering temperature 800 °C. Far infrared spectra analysis showed the structural phonon oscillation at infrared region played an important role in polarization. Nd_2Zr_3(MoO_4)_9 ceramics obtained the optimum microwave dielectric properties of ε_r= 10.01, Q×f= 55,923 GHz, τ_f= - 13.81 ppm/ °C when sintered at 800 °C for 6 h.