Alumina Template (alumina + template)

Distribution by Scientific Domains

Selected Abstracts

Vertically Aligned Nanowires on Flexible Silicone using a Supported Alumina Template prepared by Pulsed Anodization

Stefan Mátéfi-Tempfli
Carpets of vertically aligned nanowires on flexible substrates are successfully realized by a template method. Applying special pulsed anodization conditions, defect-free nanoporous alumina structures supported on polydimethylsiloxane (PDMS), a flexible silicone elastomer, are created. By using this template with nanopores ending on a conducting underlayer, a high-density nanowire array can be simply grown by direct DC-electrodeposition on the top of the silicone rubber. [source]

Nanotubes: A Closer Look Inside Nanotubes: Pore Structure Evaluation of Anodized Alumina Templated Carbon Nanotube Membranes Through Adsorption and Permeability Studies (Adv. Funct.

In the "heart" of nanotubes. The internal morphology of carbon nanotubes (CNTs) is assessed by investigating the permeability and adsorption behavior of selected gases and vapors through CNTs that have been grown inside the channels of an anodized alumina template, as presented by G. E. Romanos, G. N. Karanikolos, and co-workers on page 2500. The cover illustrates template-free aligned CNTs in a heart-like configuration. Internal restrictions, surface roughness, hollow space narrowing, and other inside-tubes characteristics are determined that are crucial in CNT storage and flow-through applications. [source]

Concentric Sub-micrometer-Sized Cables Composed of Ni Nanowires and Sub-micrometer-Sized Fullerene Tubes,

F. Tao
Abstract Highly ordered arrays of submicrometer-sized coaxial cables composed of submicrometer-sized C60 and C70 tubes filled with Ni nanowires are successfully prepared by combining a sol,gel method with an electrodeposition process. The wall thickness of the submicrometer-sized tubes can be adjusted by the concentration of fullerenes and the immersion time. The thermal stability of the submicrometer-sized C60 tubes is studied by Raman spectroscopy and it is found that these structures can be easily decomposed to form carbon nanotubes at relatively low temperatures (above 573,K) in an alumina template. These novel coaxial cable structures have been characterized by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), scanning electron microscopy (SEM), field-emission SEM (FESEM), Raman spectroscopy, elemental mapping, energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), vibrating sample magnetometer (VSM) experiments, and superconducting quantum interference device (SQUID) measurements. Magnetic measurements show that these submicrometer-sized cables exhibit enhanced ferromagnetic behavior as compared to bulk nickel. Moreover, submicrometer-sized C70/Ni cables show uniaxial magnetic anisotropy with the easy magnetic axis being parallel to the long axis of the Ni nanowires. C70/Ni cables also exhibit a new magnetic transition at ca.,10,K in the magnetization,temperature (M,T) curve, which is not observed for the analogous C60/Ni structures. The origin of this transition is not yet clear, but might be related to interactions between the Ni nanowires and C70 molecules. There is no preferred magnetization axis in submicrometer-sized C60/Ni cables, which implies that the Ni nanocrystals have different packing modes in the two composites. These different crystalline packing modes lead to different magnetic anisotropy in the two composites, although the Ni nanocrystals have the same face-centered cubic (fcc) structure in both cases. [source]

Synthesis of Vertical High-Density Epitaxial Si(100) Nanowire Arrays on a Si(100) Substrate Using an Anodic Aluminum Oxide Template,

T. Shimizu
Growth of vertical epitaxial Si(100) nanowires on Si(100) substrates is demonstrated (see figure) using a combination of an anodic aluminum oxide template, catalytic Au particles embedded in nanopores directly on the Si substrate by using electroless deposition, and vapor,liquid,solid growth using SiH4. HF acid treatment of the porous alumina template is important to realize a direct contact between deposited Au in the AAO nanopores and the Si substrate. [source]

Template-Assisted Fabrication of Dense, Aligned Arrays of Titania Nanotubes with Well-Controlled Dimensions on Substrates,

S. Sander
Dense arrays of vertically aligned titania nanotubes (see Figure) are created directly on silicon substrates by combining atomic layer deposition with an alumina template-based fabrication approach. This method enables excellent control over the nanotube dimensions, including their wall thickness, diameter, and height. Nanotubes were fabricated with tube walls thin enough (<,3,nm) to exhibit a wall-thickness- dependent blue-shift in the optical absorption spectra of the arrays. [source]