Dielectric tunable properties of Ba0.6Sr0.4TiO3–BaZn6Ti6O19 microwave composite ceramics

Composite ceramics based on Ba0.6Sr0.4TiO3 and BaZn6Ti6O19 are prepared by conventional solid-state reaction method. The sintering temperatures of the composites can be decreased by 100–200 °C compared with pure Ba0.6Sr0.4TiO3. The microstructures and dielectric tunable properties of the composites have been investigated. The dielectric constant is tailored from 7200 of pure Ba0.6Sr0.4TiO3 to 2400 of 10 wt% doped BaZn6Ti6O19 and 400 of 60 wt% content of BaZn6Ti6O19; the tunability measured at 30 kV cm−1 is 41.4% for 10 wt% doped BaZn6Ti6O19 and 22.5% for 60 wt% content of BaZn6Ti6O19, both of which are sintered at 1200 °C. The Q value of 60 wt% content of BaZn6Ti6O19 is 154. The high tunability and high Q value of the samples indicate that the Ba0.6Sr0.4TiO3–BaZn6Ti6O19 composite ceramics are potential applicable materials for microwave tunable devices.