Effect of Zr⁴⁺ substitution on ferroelectric and dielectric properties of BaTiO₃ ceramics

A lead-free system, BaTi_(1−x)Zr_xO₃, with x varying from 0.00 to 0.15 (in steps of 0.05), were prepared by solid state reaction method. X-ray diffraction study confirms the perovskite-type tetragonal structure with, a = 4.003 Å and c = 3.998 Å for pure BaTiO₃ and a = 4.027 Å and c = 4.023 Å for pure BaTi_0.85Zr_0.15O₃. Microstructure changes, with Zr⁴⁺ in BaTi_(1−x)Zr_xO₃, are studied using scanning electron microscopy (SEM). Dielectric constant measurements show the maximum dielectric constant value (~ 9445) for a composition, BaTi_0.85Zr_0.15O₃. P-E loop measurements support ferroelectric nature for all the samples and maximum polarization value (~10.55 µC/cm²) with squareness ratio ~0.6, at electric field 7.11 kV/cm, is obtained for BaTi_0.85Zr_0.15O₃ composition. All the measured properties suggest that the BaTi_0.85Zr_0.15O₃ may be suitable for memory device applications.