title: Focused ion beam preparation of atom probe specimens containing a single crystallographically well-defined grain boundary.
abstract: Needle-shaped atom probe specimens containing a single grain boundary were produced using the focused ion beam (FIB) of a two-beam FIB/SEM (scanning electron microscope) system. The presented specimen preparation approach allows the unprecedented study of a grain boundary which is well characterised in its crystallographic orientation by means of the field ion microscope (FIM) and the tomographic atom probe (TAP). The analysis of such specimens allows in particular the determination of solute excess atoms at this specific grain boundary and hence the investigation of the segregation behaviour. The crucial preparation steps are discussed in detail in the present study for the Sigma 19 a {331} 110 grain boundary of a 40 at.ppm-Bi doped Cu bi-crystal. Transmission electron microscope (TEM) images and TAP analyses of the atom probe tips demonstrate unambiguously the presence of the selectively prepared grain boundary in the apex region of some of the specimens.
authors.affiliation: Laboratorium für Elektronenmikroskopie, Universität Karlsruhe (TH), Engesserstr. 7, D-76131 Karlsruhe, Germany. f.perez-willard@smt.zeiss.com
authors.forename: Fabián
authors.initials: F
authors.lastname: Pérez-Willard
authors.forename: Daniel
authors.initials: D
authors.lastname: Wolde-Giorgis
authors.forename: Talaát
authors.initials: T
authors.lastname: Al-Kassab
authors.forename: Gabriel A
authors.initials: GA
authors.lastname: López
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Mittemeijer
authors.forename: Reiner
authors.initials: R
authors.lastname: Kirchheim
authors.forename: Dagmar
authors.initials: D
authors.lastname: Gerthsen