Structural, vibrational and band gap tunability of lead-free (1 − x)NaBiTO 3 –xBiMnO 3 ceramics

We report the band gap tunability of (1 − x)Na0.5Bi0.5TiO3–xBiMnO3 (x = 0.00, 0.05, 0.10 and 0.15) ceramics by a solid-state reaction method. X-ray diffraction (XRD) analysis confirmed the phase formation of rhombohedral structure with the space group of R3c. Rietveld refinement of XRD data revealed that the structural symmetry as a function of x composition. Raman analysis exhibited the vibrational phonon frequencies associated with Bi–O, Na–O, and TiO6 octahedral vibrations. The realized band gap energy variations (3.35–2.53 eV) suggesting that the synthesized ceramics materials are promising for photovoltaic and photocatalytic applications.