Synthesis,structural analysis and dielectric properties of Ba8(Mg1−xZnx)Nb6O24 hexagonal perovskites

Ba₈(Mg_1−xZn_x)Nb₆O₂₄ (x=0, 0.2, 0.4, 0.6, 0.8 and 1) ceramics were prepared through the conventional solid-state route. The materials were calcined at 1250 °C and sintered at 1375–1425 °C. The structure of the system was analyzed using X-ray diffraction and vibrational spectroscopic studies. The microstructure of the sintered pellet was analyzed using scanning electron microscopy. The dielectric constant (ε_r), temperature coefficient of resonant frequency (τ_f) and the unloaded quality factor (Q_u) were measured in the microwave frequency region. The τ_f values of the compositions were reduced by varying the value of x from 0 to 1. The dielectric responses to frequency were also studied in the radio frequency region. The compositions have good microwave dielectric properties and hence are suitable for dielectric resonator applications.