Fabrication of conducting GeSi/Si micro- and nanotubes and helical microcoils

Abstract

Conducting micro-and nanotubes and free-standing flexible helical microcoils have been fabricated from strained Ge x Si 1−x /Si heterolayers. The fabrication technique was based on self-rolling of a thin highly strained epitaxial Ge x Si 1−x /Si bifilm detached from the substrate by selective etching of a sacrificial layer in a roll-shaped tube. The obtained tube diameters varied from 10 nm to 13 µm, depending on the thickness and lattice mismatch of the GeSi/Si bilayer. GeSi/Si tubes and helical coils, up to 70 nm in diameter, exhibit good conducting properties and high mechanical strength.

Natural vibrations in a system of nanotubes

“…), including nanotubes aligned horizontally on the substrate, were developed in [13][14][15]. Effective physical properties of such films essentially depend on their structure and on the residual stress.…”

“…For the tubes, finite elements corresponding to a piezoelastic material were employed. The calculations were performed for materials commonly used in fabrication of substrates and nanotubes [13][14][15]. The properties of the materials were borrowed from [19,20].…”

On the Eigenfrequencies of an Ordered System of Nanoobjects

“…), and various substrate bonding conditions. We consider the same materials of the substrate and the nanotubes used in [15,21]. The properties of these materials are taken from [8], and the geometrical parameters are taken from [15,21].…”

“…We consider the same materials of the substrate and the nanotubes used in [15,21]. The properties of these materials are taken from [8], and the geometrical parameters are taken from [15,21]. The calculations show that for any bonding of the substrate, it is possible to choose the problem parameters in such a way that the natural frequencies of the nanotubes and the substrate can be extracted from the general spectrum of the large system.…”

“…ZnO nanocrystals are of considerable interest for nanomechanics and nanophotonics and can be fabricated by different techniques. The array of GaAs, GeSi nanotubes growing horizontally on a substrate may be obtained by technology described in [15,21]. The interest to the arrays of hollow sphere-like nanoparticles is motivated by possible applications to modeling of fullerenes, dendrimers, micelles, vesicles, and liposomes.…”