Piezoelectric and other physical properties are significantly enhanced at (or near) a morphotropic phase boundary (MPB) in ferroelectrics. MPB materials have attracted significant attention owing to both fundamental physics as well as the possibility of well-regulated energy and information storage devices which are dominated by lead (Pb)-based materials. Here, we report the crystal structure, Raman spectra, dielectric constant and polarization near the MPB of lead free (1− x) Na 0.5 Bi 0.5 TiO 3− x BaTiO 3 (0.00⩽ x⩽ 0.10) solid-solution, prepared by sol–gel auto combustion technique and sintered by microwave sintering technique. With the addition of BaTiO 3 into Na 0.5 Bi 0.5 TiO 3, it induces a structural phase transition from R3c (a single phase) to R3c+ P4mm (a dual phase) close to x= 0.06 and 0.07 and transform to a high symmetry tetragonal phase P4mm at higher compositions (x= 0.08 to 0.10) as evident from our x-ray Rietveld refinement and Raman spectroscopic results. We perform first-principles calculations based on density functional theory that confirm a structural transition from a rhombohedral to a tetragonal phase under increasing x. In the prepared solid solution, an anomalous enhancement of remnant polarization () was observed for x= 0.06 and 0.07, which has been explained based on the existence of the MPB. On the other hand, the value of coercive field was found to be decreased linearly from x= 0.00 to 0.06; it is constant for higher compositions. Further details of the ferroelectric properties on the electric field poled samples have been studied and compared with the as-grown (unpoled) samples.