Point Defects and Induced Magnetic Anisotropy in Fast Neutron Irradiated Iron

Abstract

Magnetic torque measurements have been made at 77 K for a single crystal disc of pure iron before and after a fast neutron irradiation at 5 K and after successive isochronal annealings at various temperatures between 77 K and 293 K. The observed torque curve after the irradiation contains both uniaxial and biaxial components. By analyzing the irradiation-induced torque and its change during isochronal annealings, the existence of 110-dumbbells has been confirmed, and the mechanism of the aggregation of interstitials and the change in their arrangements predicted theoretically by Bullough and Perrin have experimentally been proved.