The atomic structure of Fe100−xCux nanoalloys: X-ray absorption analysis

The local atomic structure of Fe100−xCux nanoalloys (x = 0, 10, 20, 40, 60, 70, 80 and 100%) has been investigated by X-ray absorption near edge structure (XANES) analysis. Local environment around copper and iron atoms in Fe100−xCux has been studied by comparing the experimental XANES with corresponding theoretical spectra calculated for several structural models. It has been established that the most probable structure of the Fe100−xCux nanoalloys for a low concentration of copper (x = 10–20%) is a homogenous bcc structure, for a high copper concentration (x = 60–80%)—a homogenous fcc structure, while at an intermediate copper concentration (about 40%) the nanoalloys have an inhomogeneous structure consisting of clusters of fcc solid solution (90%) and of clusters of bcc solid solution (10%).