Extended Solubility and Martensitic Hcp Nickel Formation in Antimony Implanted Nickel

摘要

Radiation damage microstructure and associated disorder have been investigated in antimony implanted nickel crystals using combined RBS and TEM analyses. In crystals implanted at and below room temperature with 80 keV Sb exp + ions to a fluence of 5x10 exp 20 m exp -2 , the retained antimony concentration in the implantation zone is approaching 15 at.%, with nearly all the antimony located substitutionally. The associated disorder as seen in the RBS analysis is insignificant. Annealing up to 600 exp 0 C has little influence on the antimony distribution, whilst the dechanneling level is reduced. TEM and diffraction analysis of room temperature implanted samples show that the radiation damage consists of dense distributions of dislocation clusters and tangles, superimposed on a rather homogeneous background of new phase particles, identified as hcp nickel. The particles have a size 0.1-0.2 mu m. The high substitutional antimony concentration at and below room temperature, which exceeds the solubility limit, indicates that its formation is thermally diffusionless and rather an effect of radiation enhanced solubility. The diffusionless nature of the microstructure is also indicated from the presence of martensitic hcp nickel, believed to form due to relief of radiation induced internal stress. (Atomindex citation 14:743977)