Controlled Synthesis of Ferromagnetic Semiconducting Silicon Nanotubes

Abstract

Recently, transition-metal-doped semiconductor nanostructures, so-called diluted magnetic semiconductors, such as dots, rods, wires, and films, have been the subject of intense research efforts due to their fascinating properties and potential applications in bioimaging, spintronics, and quantum interference information processing. Here, we present a method for synthesizing superdiluted Ni-doped ferromagnetic silicon nanotubes (SiNTs) (with room-temperature ferromagnetism), with minimal synthetic steps and with maximal control of the resultant SiNTs structure and composition. The unique advantage of our approach is the simplicity that provides us precise control of the ferromagnetic SiNT parameters, length, outer and inner diameter, wall thickness, Ni concentration, and crystallinity, by changing the template membrane (pore diameter), dipping time in the catalyst, growth time, and decomposition temperature. Numerous combinations of SiNT parameters can therefore be prepared that can influence their magnetic and electronic properties. This level of control can lead to novel future nanoelectronic and nanospintronic devices.

Biorecognition Layer Engineering: Overcoming Screening Limitations of Nanowire-Based FET Devices

“…Specifically, semiconducting nanowires (and nanotubes) have emerged as remarkably powerful building blocks in nanoscience. − Nowadays, semiconductor nanowires can be synthesized with a fine control over all key parameters, including diameter, length, chemical composition, and doping/electrical properties and shape − with the ability to create large-scale arrays of discrete nanowire elements. , Furthermore, over the past decade nanowire-based electronic devices have been demonstrated as a powerful and universal sensing platform, demonstrating key advantages such as rapid, direct, highly sensitive multiplexed detection, for a wide-range of biological and chemical species. − These devices overcome the handicapping limitations of planar FET devices by virtue of their one-dimensional (1D) nanoscale morphology . The extremely high surface-to-volume ratios associated with these nanostructures make their electrical properties extremely sensitive to species adsorbed on their surfaces, down to the detection of single molecules .…”

Controlled synthesis of anatase TiO2 nanotube and nanowire arrays via AAO template-based hydrolysis

“…Compared with the conventional modied template-directed synthesis method, the key attractive advantages of alcoholate hydrolysis can be concluded as follows: (1) the reaction commences under neutral pH condition and thus does not degrade the AAO template from corrosion, resulting in superior nanostructure quality, because amorphous alumina dissolves at either $pH < 4 or pH > 9; 33 (2) amorphous AAO can withstand the annealing temperature required to synthesize metal oxides, such as anatase TiO 2 ; (3) element-modied TiO 2 nanoarrays, or other complex oxide compounds such as perovskite titanates, can be prepared easily by adding other elemental species; (4) the most remarkable attribute of our method is that the wall thickness of NTs can be tuned easily, which is not common with other methods. 34 In our work, TiO 2 NTs with controllable wall thickness and NWs were successfully prepared by adjusting the molar concentration of reactants. Moreover, the crystal phase, microstructure and optical properties of the synthesized TiO 2 NT and NW arrays/AAO composite nanostructures were investigated.…”

Vertically Aligned Nanostructured Topographies for Human Neural Stem Cell Differentiation and Neuronal Cell Interrogation

“…Engineered VA‐NSs have been used in cell biology since the early 2000s, with carbon nanopillars and silicon nanowires (SiNWs) the early pioneers of this promising technology. [ 17–19 ] These vertically configured nanostructures—nanowires, [ 20–23 ] nanocones, [ 24 ] nanopillars, [ 25,26 ] nanostraws, [ 27,28 ] nanotubes, [ 29 ] and nanoridge arrays—have emerged as powerful tools due to their ability to interact with cells at nanoscale dimensions (the same scale as cell–cell interactions) while simultaneously harnessing unique material properties, such as photoluminescence, [ 30 ] electrical conductivity, [ 31 ] photoelectrochemical reactivity, [ 32 ] and thermal qualities. [ 31 ] Other key advantages are their localized interfacial interactions with precise spatiotemporal resolution, geometric/architectural flexibility, the capacity to interact with minimal invasiveness and perturbation, and ability to massively interface with large numbers of cells.…”