An EXAFS and computer modelling study of calcium titanite

Calcium titanite CaTiSiO5 undergoes a phase transition at similar to 220 de grees C. Extended X-ray Absorption Fine Structure (EXAFS) spectra of both c alcium and titanium K-edge have been collected and local structural informa tion extracted from them. The results have been compared with the existing XRD data on this material and the agreement is excellent. In particular, th ere is good agreement on the changes in bond lengths that occur at the phas e transition. A complementary computer simulation study has also been perfo rmed and defect formation energies have been calculated.