Amorphization of intermetallic compounds under irradiation - A review

This is a review of the field of irradiation-induced amorphization of intermetallic compounds. It includes an update of recent experimental results using in-situ particle irradiation showing the effects of dose rate, temperature, crystal orientation, electron energy and the presence of stacking faults. The review describes amorphization by ion, electron and neutron irradiation in the context of a kinetic description, where the rate-limiting step is the accumulation of enough radiation damage in the lattice opposed by thermal annealing. Stability criteria, thermodynamic or otherwise, are combined with kinetics of radiation damage and annealing to provide an overall description of the amorphization process, and of the experimentally measured critical dose and critical temperature of amorphization. From the experimental observations, it is proposed that irradiation-induced amorphization in intermetallic compounds is an entropy-driven transformation, caused by the need of the material to maintain short-range order while accommodating the random ballistic motions of the atoms caused by irradiation.