Studies on structural, dielectric and optical properties of (BaCa) (TiSn) Na Nb O lead-free ceramics.

(BaCa) (TiSn) Na Nb O (BCNTSNO) lead-free ceramics with compositions ( = 0.75, 0.8 and 0.85) were synthesized through the traditional solid-state reaction method. X-ray powder diffraction analysis showed the formation of a single phase compound crystallized in tetragonal space group 4. The evolution of Raman spectra displayed a disorder introduced into the structure, which favors a ferroelectric relaxor behavior. The dependence of the dielectric properties on temperature exhibited two composition ranges with different behaviors. Ferroelectric relaxor properties were observed for the compositions < 0.85 and the classical ferroelectric behavior for = 0.85. Lead free (BaCa) (TiSn) Na Nb O ceramics exhibited larger dielectric constants than those of parent crystal NaNbO, suggesting that it is a good candidate for lead-free ceramics in several industrial applications. Using UV-Vis spectroscopy, the optical band gap energy of ceramics (BaCa) (TiSn) Na Nb O is found at 2.89, 2.92, and 3.05 eV for = 0.75, 0.8 and 0.85, respectively.