Diffusion Characteristics of Radiation Defects in Iron: Molecular Dynamics Data

Temperature dependences of the diffusion characteristics of radiation defects, namely, clusters of up to five self-interstitial atoms (SIAs), were studied by the molecular dynamics method for bcc Fe at temperatures in the range of 300-1200 K. The above-mentioned diffusion characteristics included the diffusion coefficient, the tracer correlation factor, the mean distance traveled between changes in the migration direction, the frequency of migration direction changes, etc. The activation energy values for diffusion and changes in the migration direction were determined for the defects of interest for different temperature ranges. The temperature and size dependences of the SIA cluster diffusion mechanism (1D vs 3D) and their potential implications for the microstructure of materials exposed to irradiation are discussed.