Direct Observation of Nanostructural Fluctuation during Radiation-Induced Amorphization

Abstract

An atomistic study of radiation-induced amorphization in the NiTi intermetallic compound was performed by using in-situ high-resolution high-voltage electron microscopy and molecular dynamics in conjunction with image simulations. Both theoretical and experimental results show that metastable nanometer-size inherent atomic clusters form and disappear during irradiation, so that a spatiotemporal fluctuation under amorphization is induced. The random formation and annihilation of such inherent nanoclusters are believed to be responsible for these fluctuations, which appear to be related to transitions between the ideal glass state and metastable, unrelaxed states in an energy-dissipative system under irradiation.