A new Li₂Mg₆TiO₉-based microwave dielectric ceramic with ultrahigh quality factor

Within the scope of this research, Li₂Mg₆TiO₉-based ceramics were prepared by a traditional solid-state sintering technique. The research analyzed the influence of lithium (Li) volatilization during the sintering process, on the phase composition, and resultant microwave dielectric performances (MIDP) of the Li₂Mg₆TiO₉-based ceramics, employing advanced analytical techniques. X-ray diffraction and Raman spectroscopy analyses indicated the emergence of a second phase Mg₂TiO₄ within the sample when the sintering temperature attained 1550 °C due to Li volatilization. The generated Mg₂TiO₄ could effectively tune the MIDP of the ceramics. Optimal MIDP of Li₂Mg₆TiO₉-based ceramics were derived from a sintering temperature of 1650 °C: dielectric constant (ε_r) = 12.78, quality factor (Q × f) = 129,010 GHz, temperature coefficient of resonant frequency (τ_f) = − 46.2 ppm/°C. Low ε_r and ultrahigh Q × f indicate that the current ceramics have potential application prospects in millimeter wave communication as substrate materials.