SEVERE CREEP OF A CRYSTALLINE METALLIC LAYER INDUCED BY SWIFT-HEAVY-ION IRRADIATION

The aim of the experiments presented in this paper was to study the me chanisms leading to the atomic transport process (plastic deformation) induced in amorphous solids by GeV heavy-ion irradiation. Ni3B/Au/Ni3 B sandwiches, composed of a crystalline Au layer of various thicknesse s and of two amorphous Ni3B layers, were irradiated at liquid nitrogen temperature with 500-MeV iodine ions. The Rutherford backscattering t echnique using a 3.6-MeV He beam was applied to determine the modifica tions:of the geometry of the sandwiches due to irradiation. The result s show a radiation-induced creep of the crystalline layer, with a stra in-rate decreasing with increasing layer thickness. This creep phenome non is due to the plastic deformation process occurring in the surroun ding amorphous layers, and is induced by ion electronic energy loss. A simple theological model is developed to quantify the observed effect s.