Long-range effects in the FePd2Au alloy under ion bombardment

The effect is studied of ion bombardment (Ar+, E = 20 keV, j =100 muA/cm(2) , F = 5 x 10(16) to 10(18) cm(-2)) and thermal annealing on the atomic and magnetic structure of the FePd2Au alloy after 80% cold plastic deformation and quenching from 1200 degreesC. It is established by the Mossbauer effect and X-ray diffraction that ion irradiation at 350 degreesC (for 1.5 to 30 min) causes formation in the disorderedface-centered-cubic matrix of a long -range atomic order (of an Fe atom sublattice at an anomalously large depth up to 20 mum, at an ion projected range of similar to 13 nm) accompanied b y ferromagnetic to asperomagnetic phase transition (T-meas = 77 K). Anneali ng at T 350 degreesC up to 30 min in the absence of irradiation does not re sult in any noticeable changes in the atomic and magnetic structure. Atom m obility (the ordered structure formation rate) in the course of irradiation at 350 degreesC is approximately the same as observed in the case of annea ling at 700 degreesC.