Nanoscale Rods Research Articles

A Soft Lithographic Approach to the Fabrication of Single Crystalline Silicon Nanostructures with Well-Defined Dimensions and Shapes

AbstractA procedure was developed for large-scale fabrication of nanometer-sized structures of single crystalline silicon with well-defined dimensions and shapes. Near-field optical lithography was used to define the nanostructures in a thin film of positive-tone photoresist with an elastomeric phase mask. The nanostructures were then transferred into the underlying silicon-on-insulator (SOI) substrate through a reactive ion etching (RIE) process. With this method, we can routinely generate silicon nanostructures ∼130 nm in lateral dimension. They can be supported on the surface of a solid substrate as a patterned array, or released into a freestanding form. The lateral dimension of these silicon structures could be further reduced to as small as ∼40 nm using stress-limited oxidation at elevated temperatures. The flexibility of this approach was demonstrated by fabricating nanoscale wires, rods, rings, and interconnected triangles of silicon. Using a two-step exposure method, the silicon nanowires can be precisely “cut” into silicon nanorods with specific lengths.

Synthesis of silicon nitride nanorods using carbon nanotube as a template

A method to prepare silicon nitride nanoscale rods using carbon nanotube as a template has been presented in this letter. The products of the reaction of carbon nanotubes with a mixture of Si and SiO2 powder in nitrogen atmosphere are β-Si3N4, α-Si3N4, and Si2N2O nanorods. The sizes of the nanorods are 4–40 nm in diameter and up to several microns in length. The formation mechanism of the nanorods has also been discussed.

Electron‐beam‐induced fabrication of metal‐containing nanostructures

AbstractAn experimental system based on a transmission electron microscope JEM‐100CX has been developed for electron beam‐induced chemical vapor deposition. Direct electron beam‐induced growth of nanometer‐wide self‐supporting rods has been performed inside the microscope operating in scanning mode by decomposition of carbonyls of chromium Cr(CO)6, tungsten W(CO)6, and rhenium Re2(CO)10. In situ phase and structure transformations under annealing inside the microscope column were studied. Nanoscale rods and strips grown from rhenium carbonyl are of special interest because, after annealing, they consist of a single pure rhenium phase. The described method of metallic nanoelements fabrication enables us to produce highly conductive nanowires and tips for application in nanoelectronics, emission electronics, and scanning tunneling microscopy.

Synthesis and characterization of carbide nanorods

THE properties and potential applications of carbon nanotubes filled with other materials have aroused much speculation1–5. Strategies for filling nanotubes include in situ growth in an arc reactor using metal/carbon composites2,5 and the capillarity-driven filling of open nanotubes using liquid reagents3,4. Here we report an alternative approach to the synthesis of nanoscale structures based on nanotubes, in which the tubes are converted to carbide rods by reaction with volatile oxide and/or halide species. In this way we have been able to prepare solid carbide nanoscale rods of TiC, NbC, Fe3C, SiC and BCx in high yield with typical diameters of between 2 and 30 nm and lengths of up to 20 urn. Preliminary studies show that these rods share the properties of the bulk materials (such as magnetism and superconductivity), suggesting that they might allow the investigation of the effects of confinement and reduced dimensionality on such solid-state properties. These carbide nanorods might also find technological applications in nanostructured composite materials.