The Enhanced Thermal Stability of (Mg(0.95)Ni(0.05))(2)TiO(4) Dielectric Ceramics Modified by a Multi-Phase Method

The thermal stability of (Mg(0.95)Ni(0.05))(2)TiO(4) dielectric ceramics has been improved by mixing with CaTiO(3) phases owing to higher positive temperature coefficients. The pure (Mg(0.95)Ni(0.05))(2)TiO(4) and the mixture phase systems of CaTiO(3)-modified (Mg(0.95)Ni(0.05))(2)TiO(4) were verified by XRD diffraction patterns to ensure the crystallite of different phases. The microstructures of the CaTiO(3)-modified (Mg(0.95)Ni(0.05))(2)TiO(4) were observed by SEM and EDS to investigate the relation between element ratios and grains. As a result, it can be seen that the thermal stability of the CaTiO(3)-modified (Mg(0.95)Ni(0.05))(2)TiO(4) can be effectively enhanced, compared with the pure (Mg(0.95)Ni(0.05))(2)TiO(4). Moreover, the radio frequency dielectric performances of CaTiO(3)-modified (Mg(0.95)Ni(0.05))(2)TiO(4) dielectric ceramics are strongly dependent upon the density and the morphology of the specimens. The champion sample with the ratio of (Mg(0.95)Ni(0.05))(2)TiO(4) and CaTiO(3) of 0.92:0.08 showed an ε(r) value of 19.2, an Qf value of 108,200 GHz, and a τ(f) value of −4.8 ppm/°C, which may encourage (Mg(0.95)Ni(0.05))(2)TiO(4) ceramics to broaden the range of novel applications and match the requirements of 5G or next-generation communication systems.