Radial nanotubes for nanoelectronics elements: structure and diffraction

Formulation of the problem. Nanotubes are promising objects for the development of nanoelectronic elements. The range of electronic properties of nanotubes can be significantly expanded by synthesizing structures on their surface. Such structures have a radial cylindrical lattice; a number of nanowires have a similar lattice. Radial crystals are a new group of cylindrical structures, the study of which is at an early stage. Therefore, it is necessary to develop both ideas about the structure of radial crystals and a method for their structural analysis. The aim. Consider the simplest radial structures and the features of diffraction by them. Results. A description of the close-packed structure of nanowires and atomic layers with bcc, fcc, and hcp radial lattices sorbed on the nanotube surfaces is proposed, taking into account the effect of radial relaxation. A linear approximation is proposed that makes it possible to quantitatively describe radial relaxation at the initial stage of block growth. The quantitative kinematic theory of Fraunhofer diffraction on achiral radial structures is considered as the basis for their structural analysis, and formulas relating the parameters of the direct and reciprocal lattices are obtained. The results of model calculations of scattering intensity distributions by layer planes of the reciprocal lattice of radial crystals and along the layer lines of their diffraction patterns are presented. Schemes of diffraction patterns of radial crystals with bcc, fcc, and hcp radial lattices are presented. The applicability of traditional selection rules and the significant dependence of the positions of pseudo-orthogonal reflections on the crystal size are shown. Practical significance. The proposed description of radial structures with bcc, fcc, and hcp radial lattices and the diffraction method of structural analysis of their achiral varieties will provide structural control of the products of their synthesis, which is necessary when carrying out a wide range of studies both at the stage of development work on the synthesis of nanoelectronic elements, and for technological control during their industrial production.