EXAFS AND XANES STUDY OF FEXAL1-X (X=0.5, 0.53, 0.60, 0.62) AND ION-IMPLANTED FE60AL40 ALLOYS

Extended X-ray absorption fine-structure (EXAFS) and X-ray absorption near-edge spectroscopy (XANES) have been used to study the local order in FexAl1-x alloys (x = 0.5, 0.53, 0.60 and 0.62). Using the same tec hnique, we also analyze the chemical disorder variations induced in Fe 60Al40 samples irradiated with N+ ions at damage rates of the order of 0.1, 0.2 and 0.9 dpa. The EXAFS results related to FexAl1-x, samples reveal that all alloys are chemically ordered. In what concerns the im planted Fe60Al40 samples, an EXAFS analysis of the experimental data c onfirms unambiguously that irradiation creates an ion beam induced che mical disorder in the material. For the damage rate of 0.1 dpa, it cor responds to a chemical disorder of about 34%. All these results are co rrelated with the evolution of the XANES fine structures that were ana lyzed theoretically with more details for the equiatomic composition.