Vacancy loop formation by 'cascade collapse' in a-Fe: A molecular dynamics study of 50keV cascades

Heavy-ion irradiations of Fe and Fe–Cr model alloys Part 1: Damage evolution in thin-foils at lower doses

“…Such a mechanism had also been postulated by Dunlop et al [11] to explain their electrical resistivity experiments in iron neutron-irradiated at 4.2K. Recent molecular dynamics simulations suggest that small, sub-microscopic vacancy clusters (as well as small, mobile interstitial clusters) are produced in individual cascades in Fe [12]. Robertson et al's observations of the appearance and growth of loops on warming from 40K to RT are also consistent with the presence of sub-microscopic vacancy clusters in uncollapsed or partially-collapsed cascades.…”

“…Deleted: ¶ Deleted: It was noticed that ... [8] ... [10] ... [5] ... [11] ... [7] ... [9] ... [6] ... [12] Figure 9 shows the same area of an Fe8%Cr specimen irradiated with 100 keV Xe + ions at RT to four successive doses in increments of 10 16 ions m -2 . The foil normal was close to [111].…”

“…Specimens could usually not be tilted by more than about [10][11][12][13][14][15] o before it became impossible to correct astigmatism. Only in a few cases was it possible to characterize completely all the loops present (for an example see Part 2).…”

Interaction Analysis between Edge Dislocation and Self Interstitial Type Dislocation Loop in BCC Iron Using Molecular Dynamics

“…On the other hand, molecular dynamics (MD) computer simulations of displacement cascades suggest direct formation of small ($1 nm) SIA loops with the Burgers vector of b ¼ a 0 2 h111i. [4][5][6][7] The explanations proposed to date have not necessarily succeeded in fully explaining this discrepancy in the Burgers vectors. 8,9) The possibility of the formation of SIA loops with the Burgers vector of b ¼ a 0 2 h111i at high density with sizes a below resolution limit of TEM of 1$2 nm can not be ruled out.…”

<i>In-Situ</i> Observation of Radiation Damage Using a Combined Facility of Electron Microscope and Heavy-Ion Accelerator(s) &mdash;History and Future Prospectives&mdash;

“…In the case of large scale molecular dynamics calculation of pure iron, about 15% among 100 cases of 50 keV cascade calculations were grouped into a channeling-like mode, the length of the elongated lobes exceeding 100 nm. 36) Possibility remains that the distant cluster might be of an interstitial type which has moved long distance by one dimensional motion. From these information, it seems also difficult to examine the whole volume of large cascade initiated from high energy PKAs because of the limitation of specimen volume in electron microscopy.…”