Quantitative HRTEM studies on local lattice distortions in strained materials systems

Under favorable experimental conditions high-resolution transmission electron microscopy (HRTEM) images of coherent structures directly reflect the projected crystal potential. Local lattice strains may then be determined from HRTEM micrographs without the comparison with image simulations. This fast procedure is particularly suited for the analysis of large areas. The strain distribution in multilayer quantum dot structures has been evaluated. A direct correlation between the red shift of the photoluminescense peak position and the local strain distribution could be established. The nonplanar dissociation of the screw-dislocation core in body-centred cubic (bcc) Mo has been revealed. At an incoherent Cu/sapphire interface indications for periodic strain concentrations have been found.