Investigation of the Nanostructures Formation in the Irradiated by γ-Quanta Single-Crystal Silicon with Ultrasonic Method

Abstract

It's determined that a phasic dynamics of deformation strengthening of single-crystal silicon irradiated by γ-quanta (with energy ~1.27 MeV) in the range of radiation absorbed doses from 10 2 up to 10 9 rad by the internal friction measurement with widely known ultrasonic resonance method. We have detected appearance the maximum on the dependence of internal friction (Q −1) from dose at 5 × 10 5 rad in the specimens of p-Si with a density of the dislocations more than 10 3 cm −2. The instability of the dislocation structures has been established in the range of doses from 10 6 up to 10 9 rad, due to the formation and accumulation in the crystal lattice of the point like and the continuous radiation defects.On the time dependence of Q −1 (t) per 1.5 -2 hours after irradiation, the maximum has been established which position depends on dose of radiation. The monotonic decrease of Q −1 (t) dependence was observed at the increase of the observation time after stopping of the specimen irradiation, which is connected with decreasing of the radiation defects densities as the result of their annihilation.