Orientation Imaging Microscopy for the Transmission Electron Microscope

摘要: The resolution limit of Orientation Imaging Microscopy in the Scanning Electron Microscope is between 20 nA and 80 nA depending on basic resolution/beam current performance SEM, sample atomic number level residual strain within it. newer technique orientation imaging transmission electron microscope, TEM, improves this by a factor five to ten. new based novel procedure for determining crystallography separate small volumes examination large series dark field images. Each image recorded different diffraction condition. This achieved using computer direct beam onto same area so that it covers all directions cone semi-apex angle 3 degrees. Analysis intensity point each images permits reconstruction pattern providing data calculate its crystal orientation. process repeated image. Image Micrograph constructed from orientations determined. shown be capable producing micrographs high spatial unstrained samples. For highly strained samples difficulties are encountered accurately indexing complicated patterns observed. Methods improve procedures involve sub-cell structure first comparison adjacent pixels then summing belonging single sub-cell. resultant improvement quality more reliable determination Examples taken studies deformed aluminum.