Electron irradiation induced buckling, morphological transformation, and inverse Ostwald ripening in nanorod filled inside carbon nanotube

Graphical abstract: - Highlights: • In-situ response of iron carbide (Fe₃C) nanorod filled inside carbon nanotube (CNT) under electron irradiation has been studied at room and high temperature. • Inverse Ostwald ripening and morphological changes in both carbon nanotube as well as nanorod are observed. • Compression generated either by electron beam heating or by shrinkage of CNT walls has been observed to be a decisive factor. • Temperature during the irradiation shows high impact on irradiation induced changes. - Abstract: The present study aims to deduce the in-situ response of iron carbide (Fe₃C) nanorod filled inside carbon nanotube (CNT) under electron irradiation. Electron irradiation on Fe₃C filled-CNT at both high and room temperature (RT) has been performed inside transmission electron microscope. At high temperature (HT), it has been found that γ-Fe atoms in lattice of Fe₃C nanorod accumulate first and then form the cluster. These clusters follow the inverse Ostwald ripening whereas if e-irradiation is performed at RT then only the morphological changes in both carbon nanotube as well as nanorod are observed. Compression generated either by electron beam heating or by shrinkage of CNT walls is observed to be a decisive factor.