Low-loss microwave dielectric ceramics in the (Co1−xZnx)TiO3 (x = 0–0.1) system

(Co1−xZnx)TiO3 (x = 0–0.1) ceramics with high relative density were prepared by the conventional solid-state reaction, followed by sintering at 1290–1380 °C. X-ray diffraction patterns illustrated that a single rhombohedral crystal structure solid solution could be formed between the two end members with 0 ≤ x ≤ 0.1. The unit cell volume slightly increased with increasing Zn content (x). The microwave dielectric properties of (Co1−xZnx)TiO3 ceramics showed a significant dependence on the Zn content, the density of the specimen, and to some extent on the morphology of the grains. Specimen using (Co0.95Zn0.05)TiO3 sintered at 1350 °C for 3 h could obtain the microwave dielectric properties as follows; an εrεr value of ∼20, a Q × f value of ∼107,000 GHz (measured at f = 9.27 GHz), and a τfτf value of −60 ppm/°C.

► Microwave dielectric properties of (Co1−xZnx)TiO3 (x = 0–0.1) have been investigated.
► Formation of single phase rhombohedral-structured solid solutions was confirmed by the XRD analysis and measured lattice parameters.
► The Q × f value can be significantly promoted through Zn substitution, which can be attributed to the change in relative density.