Crystal structure, infrared spectra and microwave dielectric properties of low-firing La2Zr3(MoO4)9 ceramics prepared by reaction-sintering process

Low-firing La 2 Zr 3 (MoO 4 ) 9 (LZM) ceramics were prepared using the reaction-sintering (RS) route for the first time. The crystal structure, sintering characteristics, microstructure and microwave dielectric properties of LZM samples were explored scientifically. A single phase, with trigonal structure in R-3c space group, was formed at 600–800 °C. Dense sample with high relative density (>92 %) and homogeneous microstructure was obtained at 650 °C. Subsequently, EDS analysis revealed that the composition was corresponding to theoretical stoichiometric ratio of chemical formula. The chemical bonds theory of complex crystals and far-infrared spectra analysis were employed to investigate the structure-property relations of LZM samples in detail. Optimum microwave dielectric properties with a dielectric constant ( ε r ) of 10.17, a quality factor ( Q·f ) of 51,578 GHz and a temperature coefficient of resonant frequency ( τ f ) of -29.55 ppm/°C were achieved in LZM sample prepared by the RS process sintered at 650 °C.