On the effect of impurities on resistivity recovery, short-range ordering, and defect migration in electron-irradiated concentrated Fe - Cr alloys

The resistivity recovery of pure and impurity-doped (0.2 - 1.5% Si, 0.15% C+N) concentrated ferritic Fe - Cr alloys after electron irradiation at 50 - 60 K has been investigated over the temperature range 110 - 390 K. A fine recovery spectrum structure consisting of five peaks has been observed over the range 135 - 230 K. Short-range ordering starts with the onset of vacancy long-range migration. Doping with both types of impurity suppresses the recovery spectrum structure over the range 160 - 220 K in a similar manner. Additional effects of impurity doping on the resistivity recovery caused by deviation from Matthiessen's rule have been analysed. A stage III peak is found at 210 K, and two peaks - at 175 K and 195 K - are interpreted as being due to the vacancy short-range migration. It is supposed that such a manifestation of short-range vacancy migration is due to a strong immobilization of self-interstitial atoms, and suppression of short-range and long-range defect annealing processes in stage I, according to a configuration-trapping mechanism similar to that of Ag - Zn alloys.