Ultra-low loss Li4+xTi2Mg7O13Fx (0 ≤ x ≤ 1.75) system microwave dielectric ceramics for LTCC applications

This study involves the preparation of Li4+xTi2Mg7O13Fx (0 <= x <= 1.75) ceramics using the solid-state reaction method. The effective inhibition of dielectric loss is achieved in Li4+xTi2Mg7O13Fx (0 <= x <= 1.75) ceramics by precisely adjusting the stoichiometric ratio of the respective materials. Furthermore, a comprehensive analysis is conducted on the crystal structure and microwave dielectric properties. Result indicates that an increased LiF content decreases the sintering temperature necessary for densifying the ceramics system by 400 degrees C. Performing sintering at a low temperature reduces Li volatilisation and enhances the relative density in the ceramics. Subsequently, a profound understanding of lattice vibrations is achieved by analysing the Raman spectra of samples. The Li4.75Ti2Mg7O13F0.75 ceramic sample exhibits the optimal microwave dielectric properties: (S.T. = 925 degrees C, epsilon r = 14.99 +/- 0.11, Q x f = 137,180 +/- 2,557 GHz, tau f = -36.51 +/- 0.31 ppm/degrees C). Among suitable materials for low temperature co-fired ceramic applications, this study shows that Li4+xTi2Mg7O13Fx (0 <= x <= 1.75) ceramics are potential candidates.