Synthesis, structural and dielectric characterization of lead free x[(Ba0.7Ca0.3)TiO3]–(1 − x)[Ba(Zr0.2Ti0.8)O3] composite

Abstract

Lead free x[(Ba0.7Ca0.3)TiO3]–(1 − x)[Ba(Zr0.2Ti0.8)O3] where x = 0.4 and 0.5 ceramic solid solution system were prepared by hydroxide co-precipitation method. These solid solution ceramics were sintered using the microwave sintering technique. The structural, dielectric and ferroelectric properties were analyzed by X-ray diffraction, scanning electron microscope, dielectric impedance spectroscopy and polarization with applied electric field measurements. From the X-ray analysis it is seen that there is formation of pure perovskite phase with coexistence of tetragonal and rhombohedral structures. Dielectric constant and loss tangent were studied as a function of frequency and temperature. Temperature dependant dielectric properties are measured in the frequency range between 1 kHz and 1 MHz. The well known diffuse phase transition (DPT) behavior of the ferroelectric material exists near the room temperature which is also confirmed from the frequency dependent dielectric spectra. The gamma (γ) values were 1.32 and 1.61 for x = 0.4 and 0.5 respectively. It confirms the ferroelectric nature of materials which is in between the normal ferroelectrics and relaxor ferroelectrics. Saturation polarization values were observed 1.28 and 1.95 µC/cm2 for x = 0.4 and 0.5 respectively with the promising coercive field.