Crystallographic characteristics and microwave dielectric properties of Ni-modified MgTa2O6 ceramics

Ni 2+ modified MgTa 2 O 6 ceramics with a trirutile phase and space group P4 2 /mnm were obtained. The correlations between crystallographic characteristics and microwave dielectric performance of MgTa 2 O 6 ceramics were systematically studied based on the chemistry bond theory (PVL theory) for the first time. The results indicate that the introduction of Ni 2+ causes a change in polarizability and the Mg–O bond ionicity, which contributes to the variation of dielectric constant. Moreover, the lattice energy, and packing fraction, full width at half maximum of the Raman peak of Ta–O bond, as the quantitative characterization of crystallographic parameters, regulate the dielectric loss of MgTa 2 O 6 ceramics in GHz frequency band. In addition, the study of sintering behavior shows that the densification and micromorphology are the crucial factors affecting the microwave dielectric performance. Typically, Ni 2+ doping on the A-site of MgTa 2 O 6 can effectively promote the Q × f values to 173,000 GHz (at 7.43 GHz), which ensures its applicability in 5G communication technology.