Structural investigation and optical properties of Fe, Al, Si, and Cu–ZnTiO3 nanocrystals

Abstract

Synthesis, morphology control, and diffuse reflectance of Fe/Al/Si/Cu–ZnTiO3 prepared using the sol-gel method and calcined at 750 °C have been inspected. The Fe, Al, Si, and Cu can interchange the Ti ions and form sols in the ZnTiO3 matrix. The microstructural and optical properties of the ZnTiO3 were affected by the dopant. X-ray diffraction patterns and FullProf software exhibited the forming of the ZnTiO3 rhombohedral phase. The introduction of Fe, Al, Si, and Cu in the rhombohedral ZnTiO3 structure results in trigonal and triclinic phases for Al and Si and monoclinic phases for Fe and Cu. The various dopants convince the topical ZnTiO3 surface morphology modification observed by SEM. The total TGA weight loss of about<3% through the heating from ambient to 700 °C for all tested samples reflects its high stability.The prepared nanocrystalline powders undergo both direct and indirect energy band transitions with a direct type, which is more probable where it needs lower energy. The bandgap value of the nanocrystalline powder is slightly increased by different doping unless Fe, which leads to its decrease. The doped samples show a significant shift in the bandgap due to the introduction of electronic level, which forms the lowest unoccupied molecular orbital within the bandgap states of ZnTiO3.