Influences of CuO addition on sintering, microstructural characteristics and microwave dielectric properties of 0.6Nd[(Zn0.7Co0.3)0.5Ti0.5]O3–0.4(Na0.5Nd0.5)TiO3 ceramics

Abstract

Abstract 0.6Nd[(Zn 0.7 Co 0.3 ) 0.5 Ti 0.5 ]O 3 –0.4(Na 0.5 Nd 0.5 )TiO 3 (NZCT–NNT) ceramics with different amounts of CuO were prepared through a traditional ceramic technique. The influences of CuO addition on the sintering, microstructural characteristics and microwave dielectric properties of the NZCT–NNT ceramics were studied in detail. Acting as a sintering aid, CuO addition improved the sinterability and promoted the densification of the NZCT–NNT ceramics due to the production of a liquid phase. The sintering temperature of the NZCT–NNT ceramics was successfully reduced from 1410 °C to 1250 °C. The addition of CuO resulted in a change in the grain shape of the NZCT–NNT ceramics, ranging from a plate-like layered shape to a round–like shape. Additionally, CuO addition adjusted the temperature coefficient of resonant frequency (τ f ) toward near–zero without inducing an obvious deterioration in the dielectric constant (e r ) and the quality factor ( Q × f ) of the NZCT–NNT ceramics. After being sintered at 1250 °C for 3 h, the NZCT–NNT ceramics to which 2.0 wt% CuO was added exhibited optimized microwave dielectric properties of e r = 48.56, Q × f = 46,420 GHz, and τ f = + 1.3 ppm/°C. The CuO–doped NZCT–NNT ceramics could find the potential commercial applications in microwave components that require low sintering temperatures.