A novel ultra-high Q microwave dielectric ceramic ZnMgTiO4 with spinel structure.

Novel ultra-high Q ceramic ZnMgTiO 4 was prepared using solid-state synthesis. For the first time, the crystal structure, sintering behaviour and microwave dielectric properties of ZnMgTiO 4 ceramic were investigated. ZnMgTiO 4 ceramics formed a cubic spinel (space group Fd 3 ‾ m) single-phase for sintering within 1340 °C-1400 °C, with Zn2+ occupying the tetrahedral site, Mg2+ and Ti4+ distributing randomly in the octahedral site, whereas a trace of MgTiO 3 appeared at 1420 °C. At 1400 °C: ϵ r = 16.8, Q × f = 202,021 GHz, and τ f = −38 ppm/°C, excellent microwave dielectric properties were obtained, and CaTiO 3 compensated the negative τ f to near-zero. A substantial 29% deviation between the measured ϵ r and the theoretical ϵ th could be attributed to the potential underestimation of ionic polarizability of Ti4+. Phillips–Van Vechten–Levine theory suggested that dielectric polarization and intrinsic loss were primarily influenced by the Ti–O bonds. As a conclusion, ZnMgTiO 4 ceramic emerges as a promising candidate for 5G/6G wireless communication devices. [ABSTRACT FROM AUTHOR]