The title compounds Ca1-xLaxTi1-xFexO3 (0.0 ≤ x ≤ 0.5) were prepared by solid state reaction at 1350°C for 24 hours. X-ray powder diffraction measurements were performed by step scanning mode.All the prepared samples were single phase of perovskite orthorhombic system and belong to the space group Pbnm. The crystal structure has been refined by Rietveld method using FULLPROF program. The exact coordinates of atoms, the unit cell dimension, isotropic temperature factors and the profile width parameters as well as the interatomic distances have been refined. It was found, that the unit cell parameters are related to the ideal perovskite cubic system and vary linearly with the cation substitution. The calculated values of the tolerance factor (t) for these compositions indicate a significant degree of distortion in the perovskite structure. The distortion decreases with increasing the substitution and maximum distortion corresponds to CaTiO3, which is consistent with the experimental results of cell distortion factor. Also, from the refined values of the crystallite size, it was found that the crystallite size increases with increasing the substituted cations.
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