Microwave dielectric properties of H3BO3–CuO co-doped 0. 85BaTi4O9–0.15BaZn2Ti4O11 ceramics

Abstract

The effects of x wt% H 3 BO 3 ? 1.0 wt% CuO (x = 1.0-10.0) co-doping on microstructure and microwave dielectric properties of 0.85BaTi 4 O 9 -0.15BaZn 2 Ti 4 O 11 (BZT) have been investigated according to the conventional solid-state reaction in this study. The X-Ray Diffraction results showed that the main crystal phase in the sintered ceramics was BaTi 4 O 9 . The addition of H 3 BO 3 -CuO resulted in the liquid phase sintering mechanism, which effectively improved their relative densities and lowered the sintering temperature. As H 3 BO 3 doping amount increased from 1.0 to 10.0 wt%, the relative density and e r displayed a sharp increase at first and then a decline when x = 6.0 wt%. The Q 9 f value experienced a continuously decrease with the addition of H 3 BO 3 when sintered at sintering temperature. The development in s f was different, increasing persistently with the increase of doping amount at different sintering temperature. The H 3 BO 3 -CuO co-doped 0.85BaTi 4 O9-0.15BaZn 2 Ti 4 O 11 ceramics had a low sintering temperature of 1000°C and a high e r value. Good microwave dielectric properties with values of e r = 35.0, Q 9 f = 20,700 GHz and s f = 12.0 ppm/°C were obtained in the BZT ceramics with 6.0 wt% H 3 BO 3 and 1.0 wt% CuO sintered at 1000°C for 2 h.