Nature and thermal stability of radiation-induced defects in zirconium hydride

Hydrogen isotope population near dislocations in zirconium from molecular dynamics

“…Interestingly, radiation is often found to enhance diffusion and permeation of hydrogen isotopes in metals [ 3 ]. Solubility and diffusivity are likely to significantly change under reactor conditions due to the formation of irradiated defects such as point defects [ 4 , 5 ] and dislocations [ [6] , [7] , [8] , [9] , [10] , [11] ]. However, these defects trap hydrogen isotopes which does not explain why radiation enhances diffusion.…”

“…There are many different types of dislocations in hexagonal close packed (HCP) α-Zr crystals. Since the main defects created during radiation cascade are vacancies and interstitials [ [4] , [5] ], the [0001]/2 intrinsic and extrinsic dislocations, corresponding respectively to removal (i.e., vacancy segregation) and addition (i.e., interstitial segregation) of a (0002) half plane, are easily formed in irradiated samples. These dislocations are on the basal plane, have an edge Burgers vector of near [0001]/2 normal to the basal plane, and typically cannot easily glide.…”