Microstructure and microwave dielectric properties of Ba4.2Nd9.2Ti18−xSnxO54(x = 0, 0.25, 0.5, 1, 1.5, 2) ceramics

Abstract

Ba4.2Nd9.2Ti18−xSnxO54(x = 0, 0.25, 0.5, 1, 1.5, 2) microwave dielectric ceramics with high Q × f value were prepared by conventional solid state route. The microstructure and microwave dielectric properties of Ba4.2Nd9.2Ti18−xSnxO54(x = 0, 0.25, 0.5, 1, 1.5, 2)(BNTS) ceramics were systematically investigated. XRD patterns showed that there was only a single BaNd2Ti5O14 phase identified in all samples and no second phase was found. SnO2 substitution increases the lattice parameters of BNT ceramic. Moreover, the bulk density of BNT ceramics increases as the x increases. Both the permittivity and τf value decrease when the Sn concentration increases. The SnO2 substitution has a big influence on Q × f value. When x = 0.5, the BNTS ceramic gains the highest Q × f value. Afterwards, the Q × f value decreases sharply when x value increases. Excellent microwave dielectric properties were achieved in Ba4.2Nd9.2Ti18−xSnxO54(x = 0.5) ceramics sintered at 1340 °C for 2 h: er = 80.6, Q × f = 9177 GHz, τf = 61 ppm/°C.