Dielectric properties of low Zr-substituted BaTi4O9 at microwave frequencies

The microwave dielectric properties and microstructures of Ba(Ti 1−x Zr x ) 4 O 9 (0≤ x ≤ 0.025) ceramics prepared using the conventional solid-state route were investigated. When x was increased from 0 to 0.0125, the Q × f value of the specimen increased from 32,600 GHz to a maximum of 63,700 GHz, and the ε r value increased from 34.6 to 35.5. The structure and microstructure were analyzed using X-ray diffraction and scanning electron microscopy. The dielectric properties were correlated with various x values. With x = 0.0125, the excellent microwave dielectric properties of ε r ~ 35.5, Q × f ~ 63,700 GHz (at 8 GHz), and τ f ~ 13 ppm/°C were obtained for Ba(Ti 0.9875 Zr 0.0125 ) 4 O 9 ceramics sintered at 1300 °C for 4 h.