Abstract <p>The structure and thermal stability of the amorphous alloy Al₈₅Ni₅Fe₇La₃ in the initial rapidly quenched state and after xenon ion irradiation with energy of 167 MeV in the range of fluence values of 10¹²–2 × 10¹⁴ ions/cm² were studied. On the basis of the modeling of defect formation profiles, the heterogeneity of the defect distribution over the thickness of the irradiated sample was found. The mean free path of xenon ions was determined, which determines the zone of maximum accumulation of radiation defects. It is in this zone that nanocrystallization with the primary precipitation of the metastable intermetallic Al₈(Fe,Ni)₂La was detected by electron microscopy methods. A comparative analysis of the alloy structure after quenching, irradiation and annealing was carried out using complex structural research methods. It is shown that irradiation leads to a decrease in the degree of short-range order in an amorphous matrix and increases the thermal stability of an amorphous nanocrystalline structure partially crystallized as a result of irradiation.</p>