The geometrical characteristics of fcc, hcp, and polycrystalline nanowires: simulations of transmission electron microscopy images and diffraction patterns

To theoretically study the physicochemical properties of nanowires, it is necessary to build the corresponding atomic geometrical models. Here we present the geometrical characteristics of nanowires with fcc, hcp, and polycrystalline structures. We consider fcc and hcp wires grown along the (111) and z axis directions, respectively, with various diameters and lengths. In addition, since staking faults in these systems are very common, we analyze also the case of nanowires formed by stacked pieces having different crystalline structures and orientations, a fact that leads to the formation of several internal interfaces. By performing simulations of transmission electron microscopy (TEM) images and diffraction patterns of the nanowires considered here, we reveal how sensitive are the calculated images to the defocus condition as well as to the orientation of the wire with respect to the incident beam, a result that must be taken into account in order to better understand the measured data.