An exafs and computer modelling study of calcium titanite

Abstract

Calcium titanite CaTiSiO5 undergoes a phase transition at approximately 220 °C. Extended X-ray Absorption Fine Structure (EXAFS) spectra of both calcium and titanium K-edge have been collected and local structural information extracted from them. The results have been compared with the existing XRD data on this material and the agreement is excellent. In particular, there is good agreement on the changes in bond lengths that occur at the phase transition. A complementary computer simulation study has also been performed and defect formation energies have been calculated.