Investigation of phase, structural, and electrical properties of BNT–BT solid solutions in the vicinity of MPB regime

The lead-free (1 − x)BNT–xBT solid solutions (x = 0.04–0.06, Δx = 0.005) were successfully synthesized by the sol–gel route. The formation of pure perovskite and morphotropic phases was confirmed by their XRD pattern and Raman spectrum. The substitution of BT enhances the local structural disorder within the crystal lattice upto x = 0.055, followed by a subsequent decrease. This trend was corroborated by measuring the dielectric, ferroelectric, and piezoelectric characteristics. The observation of highest εr (~ 1173 at 1 kHz), Ps (~ 39.82 μC/cm2), Pr (~ 31.13 μC/cm2), S (~ 0.17%), and d33 (~ 105 pC/N) for x = 0.055, suggest the credibility of ceramics inside the MPB regime. Its scaling exponents (α ~ − 6.50 and β ~ 1.90 at high E0) from dynamic hysteresis loops revealed good polarization reversal behavior.