The positron response of simulated stacking-fault tetrahedra in Cu was investigated. It was found that, in both regular and truncated stacking-fault tetrahedra, the positron lifetimes were about 10 to 15ps longer than the bulk lifetimes. This was an indication that the vacancy-like defects observed in neutron-irradiated Cu by positron annihilation lifetime measurements did not arise during the formation of the stacking-fault tetrahedra but rather during the interaction of the stacking-fault tetrahedra with other defects.

Positron Lifetime Calculations for Stacking Fault Tetrahedra in Copper. S.Van Petegem, J.Kuriplach, P.M.Derlet, H.Van Swygenhoven: Physica Status Solidi C, 2007, 4[10], 3514-7