Microwave dielectric properties of low loss Li2(Mg0.95A0.05)3TiO6(A = Ca2+, Ni2+, Zn2+, Mn2+) ceramics system

• The effects of different bivalent A2+(A2+ = Ca2+, Ni2+, Zn2+, Mn2+) substitution for Mg were firstly investigated.
• Zn-substitution for Mg had a significant effect on the Q × f and τƒ of the ceramics compared to that of pure Li2Mg3TiO6.
• The Li2(Mg0.95Zn0.05)3TiO6 ceramics sintered at 1275 °C exhibited excellent microwave dielectric properties of ɛr∼14.6, Q × f∼158,000GHz, τƒ∼+3.2 ppm/°C.

Ultra low loss microwave dielectric materials of Li2(Mg0.95A0.05)3TiO6(A = Ca2+, Ni2+, Zn2+, Mn2+) ceramics were investigated through conventional solid-state reaction method. The effects of different bivalent A2+(A2+ = Ca2+, Ni2+, Zn2+, Mn2+) substitution for Mg on the phase composition, microstructure and microwave dielectric properties were systematically discussed. The XRD patterns indicated that the main peaks belonged to Li2Mg3TiO6, and little impurities were formed. We have found that Zn-substitution for Mg, which could increase its Q × f value and lower the |τƒ| compared to that of pure Li2Mg3TiO6, had a significant effect on the Q × f and τƒ of the ceramics. Li2(Mg0.95A0.05)3TiO6 ceramics specimens with A = Zn2+ sintered at 1275 °C for 6h exhibited excellent microwave dielectric properties of ɛr∼14.6, Q × f∼158,000GHz (at 9.11GHz) and a near-zero τƒ∼+3.2 ppm/°C.