Sintering characteristics and microwave dielectric properties of low loss CoZrNb2O8 ceramics achieved by reaction sintering process

The low loss microwave dielectric materials CoZrNb2O8 with monoclinic wolframite structure were prepared by the reaction sintering process based on conventional solid-state method. The samples were characterized by means of X-ray diffraction, scanning electronic microscopes and energy dispersive X-ray spectroscopy, and the microwave dielectric properties of these samples were investigated using the network analyzer. The results showed that the dielectric properties are strongly dependent on the composition, densification and microstructure of the specimens. Out of these compositions, CoZrNb2O8 with nearly full density obtained at the lower sintering temperature of 1250 degrees C with excellent microwave properties of epsilon(r) value of 24.40, Q.f of 43,123 GHz and tau(f) of -46.99 ppm/degrees C. To evaluate the effects of intrinsic factors on the microwave dielectric properties, the chemical bond properties were calculated based on the chemical bond theory. (C) 2016 Published by Elsevier B.V.