Structure refinement of polycrystalline orthorhombic calcium titanate substituted by lanthanum: Ca1-x La x TiO3 (x=0.1-0.4)

Polycrystalline phase of composition Ca1 - x La (x) TiO3 (x = 0.1-0.4) has been synthesized by ceramic route at 1050A degrees C. The material has been characterized by its typical powder X-ray diffraction pattern. The structural refinement has been carried out by step data analysis using Rietveld method and General Structure Analysis System software. The material crystallizes at room temperature in Pbnm (#62) space group with lattice parameters a = 5.2241(4) , b = 5.7500(4) , c = 7.9629(5) and Z = 4. The Rietveld refinement converged to the final structure model giving profile indicator, residual parameter (R (p) ) = 12.27% and goodness of fit = 1.78. Major interatomic distances, bond angles, and structure factors have been calculated using General Structure Analysis Software programming a step data analysis of the compound. The metal-oxygen bond lengths are in good agreement with their standard values reported for these oxides. The crystal morphology has been examined by scanning electron microscopy. The Energy Dispersive X-ray analysis of the specimen shows that the lanthanum enters into the structural framework of CaTiO3.