Characteristics of High-Q Microwave Dielectric Ceramics Nd(Co1/2Ti1/2)O3 With CuO Addition

We report the microwave dielectric properties and the microstructures of Nd(Co_1/2Ti_1/2)O₃ ceramics prepared by the conventional solid-state route. The prepared Nd(Co_1/2Ti_1/2)O₃ exhibits a mixture of Co and Ti showing a 1:1 order in the B site. Lowering the sintering temperature (as low as 1260°C) and promoting the densification of Nd(Co_1/2Ti_1/2)O₃ ceramics could be effectively achieved by adding CuO (up to 0.75 wt%). At 1350°C, Nd(Co_1/2Ti_1/2)O₃ ceramics with 0.5 wt% CuO addition possess a dielectric constant (ɛ_r) of 27.6, a Q × f value of 165 000 GHz (at 9 GHz), and a temperature coefficient of resonant frequency (τ_f) of −20 ppm/°C. By comparing with pure Nd(Co_1/2Ti_1/2)O₃ ceramics, incorporating additional CuO helps to render a dielectric material with a higher dielectric constant, a smaller τ_f value, and a 20% dielectric loss reduction, which makes it a very promising candidate for applications requiring low microwave dielectric loss.