Microstructure and Raman spectra analysis of [(Zn0.8Mg0.2)1-xNix]2SiO4 microwave dielectric ceramics featuring low relative permittivity and low dielectric loss

A solid-state reaction method was successfully employed to synthesize [(Zn 0.8 Mg 0.2 ) 1-x Ni x ] 2 SiO 4 microwave dielectric ceramics by partially substituting [Zn 0.8 Mg 0.2 ] 2+ with Ni 2+ ions. XRD analysis indicated that the proportion of the primary Zn 2 SiO 4 phase decreases with increasing Ni 2+ content, while the secondary MgNi(SiO 4 ) phase becomes predominant. This phase transition contributes to a reduction in dielectric loss. The sintering behavior, phase composition, microstructure, and microwave dielectric properties of the ceramics were systematically investigated. The incorporation of Ni 2+ ions lowered the optimal sintering temperature from 1325 to 1400 °C. SEM analysis revealed that an optimal Ni 2+ substitution level enhanced the grain density within the [(Zn 0.8 Mg 0.2 ) 1-x Ni x ] 2 SiO 4 ceramic matrix. The relationship between Q × f and the average grain size as well as grain uniformity was analyzed. The trend of τ f is primarily governed by the total V izn-o and E zn-o . Additionally, the relationship between lattice vibrations, Raman shifts, and dielectric properties was investigated using Raman spectroscopy. Certainly, the [(Zn 0.8 Mg 0.2 ) 0.8 Ni 0.2 ] 2 SiO 4 ceramic, sintered at 1325 °C, exhibits an exemplary set of microwave dielectric properties: an εr value of 6.8, a Q × f value of 27,185 GHz, and a τ f value of − 37 ppm/ °C.