Investigation of effect of template geometry on the crystal structure of Ni nanotubes

Modifications of geometric characteristics and structural properties of Ni nanotubes obtained by template synthesis were considered in this research study. Ion-track polyethylene membranes with pores diameters in the range from 180 to 380 nm were used as templates. Methods of scanning and transmission electron microscopy, energy dispersive and X-ray analysis were used to find influence of the geometrical properties of templates on structure, phase and elemental composition. X-ray analysis showed polycrystalline FCC-structure of nanotubes with crystal lattice parameters different from the standard values, indicating the presence of microstresses in the structure and microdistortions of lattice. We have made a hypothesis of the effect of template parameters on the crystal structure. With the increase of pores diameter, a predominance tendency of traversal of NT axis growth to longitudinal appeared, which could be explained by the increase of the deposited atoms quality. In this case, a tangential crystallites growth dominates over the growth in the normal direction due to layer-by-layer growth process.