Crystal structures, lattice vibrational characteristics, and dielectric responses of ZnWO4 microwave dielectric ceramics sintered at different temperatures

Abstract

The study meticulously examined the impact of varying sintering temperatures on the phase transformations, crystallographic configurations, dielectric response mechanisms, and lattice vibrational characteristics of the ZnWO4 ceramics. Far-infrared reflectance spectra were fitted using a four-parameter semiquantum model to obtain the intrinsic dielectric properties. Moreover, the contribution to the dielectric properties for each vibrational mode was analyzed, indicating that the lower-frequency mode had the most contribution. The relationship linking the structural aspects to the properties of ZnWO4 ceramics was elucidated through an analysis of the Raman spectral modes across a range of sintering temperatures, overcoming the limitation of solely textual description without mathematical quantification. When sintered at 1070 °C, the ZnWO4 ceramic had the best dielectric properties: εr = 14.81, Q×f = 34,239 GHz (f = 9.69 GHz), with the highest relative density of 96.95 %.