Structural, dielectric, impedance and modulus studies of lead-free (1 − x)Bi0.5Na0.5TiO3−xBaTiO3(x = 0,0.06,0.08)-based ceramics

Lead free (1 − x )Bi 0.5 Na 0.5 TiO 3 − x BaTiO 3 ; x = 0.0, 0.06 and 0.08 solid solution in the proximity of morphotropic phase boundary were synthesized by conventional solid state technique. The addition of BaTiO 3 is found to affect the structural and dielectric properties of Bi 0.5 Na 0.5 TiO 3. It was evidenced by X-ray diffraction that the samples exhibit the combination of two phases orthorhombic (major) and minor traits of tetragonal phase. Scanning electron micrograph revealed the regular-shaped grains with dense microstructure. The dielectric properties of the synthesized samples were studied in wide frequency range (100 Hz–1 MHz) at various temperatures upto 450 °C. From impedance and modulus spectroscopy it has been found that there exists a non-Debye relaxation in the synthesized samples. The contribution of capacitance of grain and grain boundary in the conduction mechanism of the synthesized samples at higher temperatures is reported. The synthesized ceramics show the negative temperature coefficient of resistivity. The studied material shows a relaxor behavior with wide operating temperature window for various dielectric, piezoelectric and ferroelectric applications.