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We present a proof-of-concept attesting the feasability to obtain orientation maps of polycrystalline materials within a conventional Scanning Electron Microscope (SEM) using a standard goniometer and Back Scattered Electron (BSE) detector. The described method is based on the analysis of the contrast variation of grains due to the channeling of incident electrons on a rotating sample. On each pixel of the map, experimental intensity profiles as a function of the rotation angle are obtained and compared with simulated ones to retrieve the orientation. From first results on aluminum polycrystals, the angular resolution is estimated to be better than one degree. [ABSTRACT FROM AUTHOR]

In situ SEM mechanical tests are key to study crystal plasticity. In particular, imaging and diffraction (EBSD) allow microstructure and surface kinematics to be monitored all along the test. However, to get a full benefit from different modalities, it is necessary to register all images and crystallographic orientation maps from EBSD into the same frame. Different correlative approaches tracking either Pt surface markings, crystal orientations or grain boundaries, allow such registrations to be performed and displacement as well as rotation fields to be measured, a primary information for crystal plasticity identification. However, the different contrasts that are captured in different modalities and unavoidable stage motions also give rise to artifacts that are to be corrected to register the different information onto the same material points. The same image correlation tools reveal very powerful to correct such artifacts. Illustrated by an in situ uniaxial tensile test performed on a bainitic-ferritic steel sample, recent advances in image correlation techniques are reviewed and shown to provide a comprehensive picture of local strain and rotation maps. [ABSTRACT FROM AUTHOR]

Abstract: We introduce diffracted electron tracking (DET), which combines two electron microscopy techniques, electron backscatter diffraction and the use of an environmental cell in a scanning electron microscope to measure changes in nanocrystal-orientation. The accuracy of DET was verified by measuring the motion of a flat gold crystal caused by the rotation or tilting of the specimen stage. DET was applied to measure the motion of semi-fixed gold nanocrystals in various environments. In addition to large motions induced in water environment, DET could detect small differences in the three-dimensional (3D) motion amplitude between vacuum environment and an Ar gas environment. DET promises to be a useful method for measuring the motion of single nanocrystals in various environments. This measuring technique may be used in a wide range of scientific fields; for example, DET may be a prospective method to track the single molecule dynamics of molecules labeled with gold nanocrystals. [Copyright &y& Elsevier]