Microwave dielectric properties of double perovskite ceramics Ba2Zn1−xCaxWO6(x=0−0.4)

The structural, vibrational and microwave dielectric properties of double perovskite ceramics Ba2Zn1−xCaxWO6(x=0−0.4) were investigated. The samples were sintered at different temperatures in the range 1300-1400 °C for 4 h. The grown samples were characterized by means of X-ray diffraction, Raman spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy analysis. Microwave dielectric properties of the samples were measured using the TE01δ resonance mode of the cylindrical pellets. The relative permittivity (εr), calculated using Clausius-Mossotti equation is found to be comparable with the experimental results. Our analysis shows that the tolerance factor (t) as well as the temperature coefficient of resonant frequency (τf) of these perovskites decreases with the increase in Ca content. The value of τf is zero for the samples with x = 0.3 and 0.4.