Temperature evolution of the crystal structure of Ca2Fe2.6S2O3

This proposal to establish the details of the crystal structure at low temperatures of the layered oxide chalcogenide Ca2Fe2.6S2O3. This will enable us to correlate the structural evolution with the the unusual change in magnetic ordering that occurs around 70K accompanied also by a change in the resistivity, and relate this to subtle changes in the details of the complex superstructure which results from Fe ion/vacancy ordering.