DISPLACEMENT THRESHOLD ENERGY OF IRON ATOMS IN AMORPHOUS AND CRYSTALLINE FE75B25 ALLOYS

Displacement threshold energy determination has been made at 21 K for amorphous a-Fe//7//5B//2//5 alloy and its crystalline c-Fe//3B counterpart. The experiment consists in measuring the electrical resistivity increase rate during a 21-K electron irradiation as a function of the incident energy of the electron beam. The results can be summarized as follows: the displacement threshold energy is the same for both alloys (22 plus or minus 3)ev; the resistivity of an induced defect is (400 plus or minus 150) mu OMEGA cm and (2700 plus or minus 700) mu OMEGA cm for the a-Fe//7//5B//2//5 and c-Fe//3B alloy respectively; with the help of 2. 4 Mev production curves, the recombination volume has been evaluated for both alloys; at a given electron dose, the irradiation induced defects concentration is higher in the amorphous than in the crystalline alloy.