Low temperature sintering and microwave dielectric properties of 0.4Nd(Zn0.5Ti0.5)O3–0.6Ca0.61Nd0.26TiO3 ceramics with BaCu(B2O5) additive

Abstract

0.4Nd(Zn0.5Ti0.5)O3–0.6Ca0.61Nd0.26TiO3 (NZT–CNT) ceramics were prepared by the conventional solid–state ceramic route with 1–7 wt% BaCu(B2O5) (BCB) powders as additives. The presence of BCB effectively reduced the sintering temperature of NZT–CNT ceramics due to the formation of a liquid phase at a relatively low temperature during sintering. Meanwhile, the addition of BCB powders inhibited the grain growth of NZT–CNT ceramics and resulted in a fine microstructure. Compared with undoped NZT–CNT ceramics, up to 3 wt% BCB additive induced the grain from spherical to square shape. By adding small amounts of BCB additive, NZT–CNT ceramics exhibited low sintering temperature and good microwave dielectric properties. Especially, the optimum microwave dielectric properties for a 5 wt% BCB–doped NZT–CNT ceramic sintered at 1050 °C for 4 h were obtained: εr = 45.6, Q × f = 38,230 GHz (f = 7.35 GHz) and τf = −8.4 ppm/°C.