Magnetic relaxation occurring in low-temperature electron-irradiated α-Fe after annealing above stage III (220 K)

After irradiation of carbon-charged α-iron with 3 MeV-electrons at 77 K and subsequent anneal above stage III (220 K), the successive development of simple relaxation processes at 155, 325, and 18 K is observed. Additional annealing experiments on electron-irradiated pure as well as on non-irradiated carbon-charged α-Fe indicate that these relaxations arise from defect configurations which are composed of both, irradiation-induced intrinsic defects – e.g. vacancies – and C-atoms. From an analysis of the relaxation times, τ = τ0 exp (Q/kT), Q = (0.041 ± 0.003) eV, τ0 = 10−11 ± 1 s are obtained for the relaxation occurring at 18 K, which is attributed to a divacancy–carbon complex.