Effect of Ion Irradiation Introduced by Focused Ion-Beam Milling on the Mechanical Behaviour of Sub-Micron-Sized Samples
Jinqiao Liu, Ranming Niu, Ji Gu, Matthew J. Cabral, Min Song, Xiaozhou Liao
Abstract
Abstract The development of xenon plasma focused ion-beam (Xe + PFIB) milling technique enables site-specific sample preparation with milling rates several times larger than the conventional gallium focused ion-beam (Ga + FIB) technique. As such, the effect of higher beam currents and the heavier ions utilized in the Xe + PFIB system is of particular importance when investigating material properties. To investigate potential artifacts resulting from these new parameters, a comparative study is performed on transmission electron microscopy (TEM) samples prepared via Xe + PFIB and Ga + FIB systems. Utilizing samples prepared with each system, the mechanical properties of CrMnFeCoNi high-entropy alloy (HEA) samples are evaluated with in situ tensile straining TEM studies. The results show that HEA samples prepared by Xe + PFIB present better ductility but lower strength than those prepared by Ga + FIB. This is due to the small ion-irradiated volumes and the insignificant alloying effect brought by Xe irradiation. Overall, these results demonstrate that Xe + PFIB systems allow for a more efficient material removal rate while imparting less damage to HEAs than conventional Ga + FIB systems.