Evolution of the local environment and magnetism in Fe60Al40 films under Ne+ irradiation

X-ray absorption spectroscopy has been applied to study the consequential changes of the local environment around Fe and its magnetic moments in Fe60Al40 thin films of 40 nm thickness along the order-disorder (B2 → A2) phase transition initiated by 20 keV Ne+ ion-irradiation with fluences of (0.75-6)×1014 ions*cm−2. The analysis of EXAFS spectra measured at the Fe K-edge at room temperature revealed an increased number of Fe-Fe nearest-neighbors from 3.47(7) to 5.0(1) and ∼ 1% of volume expansion through the transition. The visualization of the Fe and Al nearest-neighbours rearrangement in the first coordination shell of Fe absorbers was done by wavelet transformations. The observed structural changes will we related to the magnetic properties of the studied samples. The results of self-consistent DFT calculations using VASP and SPR-KKR program packages on relaxed Fe60Al40 structures are consistent with the experimental findings for the ordered (B2) and the disordered (A2) phases.