Defect evolution in Ni and NiCoCr by in situ 2.8 MeV Au irradiation.

The evolution of radiation-induced defects in Ni and the single-phase concentrated solid solution alloy, NiCoCr, were investigated during in situ 2.8 MeV Au ion irradiation and post-irradiation analysis using transmission electron microscopy. Compared to Ni, both the size and area density of defect clusters decreased in NiCoCr under the same irradiation conditions, suggesting that the chemical complexity, i.e., randomness of lattice site occupations, of NiCoCr suppressed radiation-induced damage. One-dimensional glide of defect clusters was observed in Ni but not in the NiCoCr alloy. The structural nature of small defect clusters in NiCoCr were further investigated using high-angle annular dark field scanning transmission electron microscopy. • Smaller and fewer defects were generated in more chemically-complicated alloys. • One-dimensional gild of defect clusters was observed in Ni but not in NiCoCr. • Both vacancy-type and interstitial-type defect clusters were identified in NiCoCr. [ABSTRACT FROM AUTHOR]