Argon Milling of Bulk and Post-FIB Specimens for Multi-Length Scale Analyses by EBSD, TEM, and APT under Controlled Environments
Correlative investigations involve structural characterization by transmission electron microscopy (TEM) combined with compositional analysis by atom probe tomography (APT) using the same specimen. A critical component of successful correlative analyses is specimen preparation; probing individual atoms requires a surface and subsurface with minimal defects, beginning with the bulk material through to the prepared specimen for TEM or APT analysis. Our previous work showed that low-energy concentrated ion beam Ar ion milling improves TEM [1] and APT [2,3] specimen quality by removing surface oxides and Ga damage caused by focused ion beam (FIB) preparation. Further enhancement in specimen quality of APT specimens is achieved in the established workflow under controlled environments, as shown in [4]. In this work, we present specimen preparation using Ar ion milling techniques not only for the APT specimen, but also the bulk sample for subsequent multi-length scale analyses by electron backscatter diffraction (EBSD), TEM, and APT under controlled environments. The removal of surface damage and oxidation, which is crucial for probing atomic layer specimens by broad and concentrated Ar ion beam milling techniques under controlled environments, is highlighted.