Foils of pure metals were irradiated with 1.25MeV electrons, at temperatures of between 110 and 323K, in a high-voltage electron microscope. In foils which had been irradiated at 300K, stacking-fault tetrahedra first formed an inhomogeneous lattice; and then voids appeared at sites which corresponded to the stacking fault tetrahedron lattice positions. At 270K, voids were found after the formation of a stacking fault tetrahedron lattice. However, voids were not observed at temperatures below 240K.

Void Formation close to Stacking Fault Tetrahedra in Heavily Electron Irradiated Pure Ag and Cu. K.Niwase, F.Phillipp, W.Sigle, A.Seeger: Journal of Nuclear Materials, 1999, 271-272, 261-5