Rietveld refinement structure, electric, dielectric and ferroelectric properties of lead-free Ba 0.985 Sr 0.015 Zr 0.10 Ti 0.90 O 3 ceramics

Ba 0.985 Sr 0.015 Zr 0.10 Ti 0.90 O 3 (BSZT) compound is prepared using the standard solid-state reaction technique to explore for energy storage applications. Samples prepared from this compound are sintered at various sintering temperatures ( T s ) of 1200, 1250 and 1300 °C, respectively. Influences of T s on the structural, morphological, dielectric and ferroelectric properties are studied in detail. Rietveld refinement is used on the X-ray diffraction pattern to confirm the crystal structure of the BSZT samples and each sample indicates the tetragonal phase with the P 4 mm space group. Interestingly, with increasing T s , the tetragonality increases up to 1250 °C, and then decreases for further increasing T s , suggesting a transformation to the cubic structure. Morphological analysis of the BSZT samples show that a dense microstructure is attained for higher T s . Temperature-dependent dielectric studies show that the degree of diffuseness increases up to 1250 °C, and then decreases for further increasing T s , suggesting a weakening of the relaxor ferroelectric behavior. A non-Debye type relaxation process in the complex impedance and the modulus spectroscopy studies confirm the significant contribution of both the grain and grain boundary to the electrical response of the studied sample. The ferroelectric behaviors of the sample are explored from the polarization versus electric field hysteresis loops. Ferroelectric properties are significantly improved with the T s .