Investigation of iron / iron oxide nanoparticles by Diffraction Anomalous Fine Structure

Diffraction anomalous fine structure (DAFS) is a recently developed technique which can provide a measurement of the local structure of a given element in a particular phase or crystallographic site. With this project, we intend to examine the applicability of the technique to highly disordered nanometer – sized iron / iron oxide core – shell nanoparticles, the diffraction pattern of which exhibits weak and greatly broadened diffraction peaks. The aim is two – fold: firstly, to test whether DAFS spectra in the near edge and extended energy regions with good signal – to – noise ratio can be recorded and, secondly, to ascertain whether differences between signals of peaks expected to have different contributions from octahedral and tetrahedral sites can be detected, in analogy to the bulk case