Influence of SrTiO3 modification on dielectric properties of Mg(Zr0.05Ti0.95)O3 ceramics at microwave frequency

The microwave dielectric properties and microstructures were investigated in the (1−x)Mg(Zr0.05Ti0.95)O3–xSrTiO3 (hereafter referred to as (1−x)MZT–xST) system. The compounds were prepared via the conventional solid-state reaction. Compositions in the (1−x)Mg(Zr0.05Ti0.95)O3–xSrTiO3 system were designed to compensate the negative temperature coefficient of the resonant frequency of Mg(Zr0.05Ti0.95)O3. The values displayed nonmonotonic mixture-like behavior, because the TiO2 phase was formed in the MZT composite ceramics with increasing x. A close zero τf of 0.2 ppm/°C could be achieved at 0.96MZT–0.04ST with ɛr = 20.8 and Q × f = 257,000 GHz.

► The microwave dielectric properties of (1−x)Mg(Zr0.05Ti0.95)O3–xSrTiO3 system have been discussed.
► The dielectric constant and τf increased; nevertheless, the Q × f decreased with an increase in x.
► Second phases were formed and affected the microwave dielectric properties of (1−x)MZT–xST system.
► ɛr of 20.8, Q × f of 257,000, and τf of 0.2 ppm/°C were obtained for the 0.06Mg(Zr0.05Ti0.95)O3–0.04SrTiO3 ceramics.
► Due to high-quality factor and near-zero τf, MZT–ST demonstrate a good potential for use in microwave devices.