High-Q Li2Mg3(Ti1−xSnx)O6 (0.02 ≤ x≤ 0.08) dielectric ceramics with low sintering temperature for LTCC application

Abstract

The crystal structure and microwave dielectric properties of Li2Mg3Ti1−xSnxO6 (0.02 ≤ x ≤ 0.08) ceramics were investigated. The crystal structure and unit cell volume of samples were obtained by Rietveld refinement. The er value had a similar trend with the pore corrected theoretical dielectric constant ecorr, which was affected by the polarizability value and molar volume. The variations of Q × f values were related to the different lattice vibrations. And the change of τƒ had a close relationship with the dielectric constant. Above all, the superior dielectric properties of ɛr ~ 13.16, Q × f~168,800 GHz, τƒ ~ − 29.8 ppm/ °C were obtained for Li2Mg3Ti0.94Sn0.06O6 ceramics sintered at 1350 °C. Furthermore, LiF was added to Li2Mg3Ti0.94Sn0.06O6 ceramics to lower the sintering temperature. The sintering behavior and dielectric properties of Li2Mg3Ti0.94Sn0.06O6-ywt%LiF (2 ≤ y ≤ 5) ceramics were also analyzed. Finally, the excellent dielectric properties of ɛr ~ 15.58, Q × f~142,210 GHz and τƒ ~ − 34.5 ppm/ °C for Li2Mg3Ti0.94Sn0.06O6-3wt%LiF ceramics were obtained sintered at 900 °C, which could be applied to the LTCC technology.