Aberration-corrected HRTEM study of incommensurate misfit layer compound interfaces

The development of spherical aberration (Cs) correctors for transmission electron microscopes offers new exciting opportunities for atomic scale investigations of solids. A main advantage of Cs-corrected HRTEM over conventional HRTEM is, that by tuning Cs to small negative values (NCSI imaging), image delocalisation can be reduced below the typical separation of atomic columns simultaneously with an optimisation of image contrast. This is an important feature when investigating interfaces in crystals, where the translation symmetry of the perfect crystal is broken and a wide range of different spatial frequencies contribute to the image contrast.