DAFS analysis of magnetite

The mechanism of the structural transformation in Fe3O4 during its Verwey t ransition at 120 K is not completely understood, partly due to the lack of knowledge of the details of the local structure around different Fe atoms i n the unit cell. In our experiment, this information was obtained at room t emperature using Diffraction Anomalous Fine Structure (DAFS) technique whic h has the ability to separately solve the local, structures around the octa hedral and tetrahedral sites in the spinel structure of magnetite. An itera tive dispersion integral algorithm was used to isolate f' and f " from the DAFS intensity and structural information was obtained from f " using stand ard XAFS analysis methods. Relevance of our results to different models of Verwey transition is discussed.