Point defects and radiation effects in B.C.C. metals

The paper gives an overview of our knowledge on intrinsic point defects in α-Fe and Ta deduced from equilibrium experiments (self-diffusion, positron annihilation) and steady-state experiments (growth of dislocation loops under irradiation in a transmission electron microscope) at elevated temperatures as well as from non-equilibrium studies (electrical resistivity, internal friction, magnetic after-effect, positron annihilation) performed at low temperatures after particle irradiation, cold-work, or quenching. It is shown that the one-interstitial model fails to explain the observations. By contrast, in the two-interstitial model a natural and internally consistent interpretation is possible, which may be extended to the other b.c.c. refractory metals. (author)