title: Specimen preparation for correlating transmission electron microscopy and atom probe tomography of mesoscale features.
abstract: Atom-probe tomography (APT) provides atomic-scale spatial and compositional resolution that is ideally suited for the analysis of grain boundaries. The small sample volume analyzed in APT presents, however, a challenge for capturing mesoscale features, such as grain boundaries. A new site-specific method utilizing transmission electron microscopy (TEM) for the precise selection and isolation of mesoscale microstructural features in a focused-ion-beam (FIB) microscope lift-out sample, from below the original surface of the bulk sample, for targeted preparation of an APT microtip by FIB-SEM microscopy is presented. This methodology is demonstrated for the targeted extraction of a prior austenite grain boundary in a martensitic steel alloy; it can, however, be easily applied to other mesoscale features, such as heterophase interfaces, precipitates, and the tips of cracks.
authors: Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA. Electronic address: mh364@drexel.edu.
authors: Matthew I
authors: MI
authors: Hartshorne
authors: Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208-3108, USA; Northwestern University Center for Atom-Probe Tomography, 2220 Campus Drive, Evanston, IL 60208-3108, USA. Electronic address: isheim@northwestern.edu.
authors: Dieter
authors: D
authors: Isheim
authors: Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208-3108, USA; Northwestern University Center for Atom-Probe Tomography, 2220 Campus Drive, Evanston, IL 60208-3108, USA. Electronic address: d-seidman@northwestern.edu.
authors: David N
authors: DN
authors: Seidman
authors: Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA. Electronic address: mtaheri@coe.drexel.edu.
authors: Mitra L
authors: ML
authors: Taheri
keywords: Atom probe tomography; Focused ion beam; Transmission electron microscopy