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

Within the scope of this research, Li 2 Mg 6 TiO 9 -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 Li 2 Mg 6 TiO 9 -based ceramics, employing advanced analytical techniques. X-ray diffraction and Raman spectroscopy analyses indicated the emergence of a second phase Mg 2 TiO 4 within the sample when the sintering temperature attained 1550 °C due to Li volatilization. The generated Mg 2 TiO 4 could effectively tune the MIDP of the ceramics. Optimal MIDP of Li 2 Mg 6 TiO 9 -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.