Dresden 2017 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 7: Analytical Electron Microscopy: SEM and TEM-based Material Analysis

MA 7.3: Vortrag

Montag, 20. März 2017, 10:45–11:00, MER 02

Quantitative materials characterization at the nanoscale with TKD in SEM — •Laurie Palasse and Daniel Goran — Bruker Nano GmbH, Am Studio 2D, 12489 Berlin, Germany

Characterization of nanostructured materials requires high spatial resolution orientation mapping at large-scale for quantitative results. Because EBSD does not achieve such resolution on bulk samples, these kind of studies are often done using a TEM. However, TEM-based orientation mapping techniques suffer from small field of view. As a result, Transmission Kikuchi Diffraction (TKD) in SEM was developed as a technique capable of delivering the same type of results as EBSD but with a spatial resolution improved by up to one order of magnitude. TKD analysis is conducted on an electron transparent sample using the same hardware and software as for EBSD system. But when using conventional EBSD geometry, the transmitted patterns (TKP) are captured by a vertical phosphor screen with a considerable loss of signal and strong distortions induced by gnomonic projection. The limitations of such sample-detector geometry are overcome by an on-axis detection system. With a horizontal phosphor screen placed underneath the sample, the transmitted signal is captured where it is the strongest and TKPs will have minimal distortions. Using low probe currents, the spatial resolution is increased and the beam-induced specimen drift reduced. The improved stability and high spatial resolution allow the user to conduct large-area TKD orientation mapping, especially when combined with a fast and sensitive EBSD detector.