Sol gel processed cadmium titanate (CdTiO3) ceramic has been characterized by X-ray diffraction (XRD), infrared (IR) and Raman techniques. The results confirm that CdTiO3 crystallizes in the pure hexagonal ilmenite phase at 900 oC and undergoes a transition to the pure orthorhombic structure above this temperature. Furthermore, it was showed that a post-annealing at the temperature of 1100 oC leads to a transition to a new phase with Pbn21 as space group, with the following lattice parameters: a = 5.30 Å, b = 5.43 Å and c = 7.57 Å. UV-Vis spectroscopy results show that CdTiO3 band gap energies are strongly affected by the crystallite size and structural properties. The obtained band gap values of ilmenite and perovskite phases are higher than those reported in the literature, whereas that of Pbn21 is slightly lower than that related to Pbnm, probably due to the distortion of Pbnm structure or to the presence of TiO2 structure.

Keywords: CdTiO3, Sol-gel, Ilmenite, Perovskite, Diffuse reflectance.