Structure, chemical bond and microwave dielectric characteristics of novel Li3Mg4NbO8 ceramics

A novel Li3Mg4NbO8 compound was fabricated through the process of solid-state reaction. The crystal structure, sinterability and microwave dielectric properties of the Li3Mg4NbO8 ceramics were investigated. XRD refinement and Raman spectra results ascertained that the Li3Mg4NbO8 compound crystallized into an orthorhombic Li3Mg2NbO6-like structure with space group Fddd. The epsilon(r) value was strongly impacted by the relative density and average ionic polarization. The Q x f value was mainly affected by the relative density and average grain size. The Li3Mg4NbO8 ceramics sintered at 1150 celcius showed outstanding microwave dielectric performance: epsilon(r) = 13.8 +/- 0.14, Q x f = 103 400 +/- 3500 GHz (at 9.6 GHz), Tau(f) = -36.0 +/- 1 ppm/celcius. Additionally, the bond characteristics were calculated for a better understanding of the structure-property correlation for Li3Mg4NbO8 ceramics.

Automated summary

A novel Li3Mg4NbO8 compound with an orthorhombic crystal structure resembling Li3Mg2NbO6 was fabricated through solid-state reaction. The microwave dielectric properties of Li3Mg4NbO8 ceramics were found to be strongly influenced by density and ionic polarization. Ceramics sintered at 1150°C showed excellent microwave dielectric performance with ε(r) = 13.8 +/- 0.14, Q x f = 103 400 +/- 3500 GHz (at 9.6 GHz), and Tau(f) = -36.0 +/- 1 ppm/°C. Bond characteristics were also calculated for a better understanding of the structure-property correlation for Li3Mg4NbO8 ceramics.