On short-range ordering in Fe-Ni alloys

In the work, the X-ray electron spectroscopy and molecular dynamics methods were used for investigating the electron and atomic structure of Fe-Ni alloys in order to explain the variations in their short-range order. The comparative study was carried out for the Fe-Ni system with the invar (Fe65Ni35) and non-invar (Fe25Ni75) compositions at two different temperatures (with heating). The presence of the invar effect in the Fe-Ni alloys can be related to strong local distortions in the fcc lattice leading to the redistributions of atoms in the nearest environment.