title: Sub-micron resolution selected area electron channeling patterns.
abstract: Collection of selected area channeling patterns (SACPs) on a high resolution FEG-SEM is essential to carry out quantitative electron channeling contrast imaging (ECCI) studies, as it facilitates accurate determination of the crystal plane normal with respect to the incident beam direction and thus allows control the electron channeling conditions. Unfortunately commercial SACP modes developed in the past were limited in spatial resolution and are often no longer offered. In this contribution we present a novel approach for collecting high resolution SACPs (HR-SACPs) developed on a Gemini column. This HR-SACP technique combines the first demonstrated sub-micron spatial resolution with high angular accuracy of about 0.1°, at a convenient working distance of 10mm. This innovative approach integrates the use of aperture alignment coils to rock the beam with a digitally calibrated beam shift procedure to ensure the rocking beam is maintained on a point of interest. Moreover a new methodology to accurately measure SACP spatial resolution is proposed. While column considerations limit the rocking angle to 4°, this range is adequate to index the HR-SACP in conjunction with the pattern simulated from the approximate orientation deduced by EBSD. This new technique facilitates Accurate ECCI (A-ECCI) studies from very fine grained and/or highly strained materials. It offers also new insights for developing HR-SACP modes on new generation high-resolution electron columns.
authors.affiliation: Laboratoire d'Étude des Microstructures et de Mécanique des Matériaux (LEM3), UMR CNRS 7239, Université de Lorraine, 57045 Metz, France; Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Université de Lorraine, France.
authors.forename: J
authors.initials: J
authors.lastname: Guyon
authors.affiliation: Laboratoire d'Étude des Microstructures et de Mécanique des Matériaux (LEM3), UMR CNRS 7239, Université de Lorraine, 57045 Metz, France.
authors.forename: H
authors.initials: H
authors.lastname: Mansour
authors.affiliation: Laboratoire d'Étude des Microstructures et de Mécanique des Matériaux (LEM3), UMR CNRS 7239, Université de Lorraine, 57045 Metz, France; Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Université de Lorraine, France.
authors.forename: N
authors.initials: N
authors.lastname: Gey
authors.affiliation: Department of Chemical Engineering & Materials Science, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Crimp
authors.affiliation: Carl Zeiss S.A.S, Division Microscopie et Systèmes, 100, route de Versailles, 78161 Marly le Roi, France.
authors.forename: S
authors.initials: S
authors.lastname: Chalal
authors.affiliation: Laboratoire d'Étude des Microstructures et de Mécanique des Matériaux (LEM3), UMR CNRS 7239, Université de Lorraine, 57045 Metz, France; Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Université de Lorraine, France. Electronic address: nabila.maloufi@univ-lorraine.fr.
authors.forename: N
authors.initials: N
authors.lastname: Maloufi
keywords: EBSD; ECCI; FEG-SEM; Gemini column; Rocking beam; SACP