Intrinsic structural defects on medium range in metallic glasses

To get insight into the structural defects on medium range in metallic glasses, molecular dynamic simulations on cavitation instability are carried out. It is found that micro voids are prone to nucleate at the sites where atomic clusters are loose packing on medium range. Close-up observation on atomic clusters around the nucleation site shows that there are two kinds of defects on medium range: cavities among the atomic clusters and boundaries between medium range orders. Further investigation shows that the defects are significantly important in both cavitation and shear transformation, which are two intrinsic deformation modes of metallic glasses.