Search

The highly ordered anodic aluminum oxide (AAO) template was fabricated using aluminum anodizing in electrolytes with two-step method, which apertures were about 50-80nm. The nickel nanowires with about 40-70nm in diameter was prepared on the AAO template by laser-MBE (molecular beam epitaxy). And high quality Raman spectra of SudanII were obtained on the glass covered with the nickel nanowires. On the nickel nanowires there are both surface enhanced Raman scattering (SERS) and tip enhanced Raman scattering (TERS). The new observations not only enlarge the range of SERS applications, but also imply a possible new enhancement mechanism. Otherwise the Raman and SERS frequencies of SudanII molecule were calculated using, respectively, DFT and B3PW91.

Anodic aluminum oxide template has a unique advantage in the preparation of nanostructure of array structure. The pore size and film thickness can be controlled by changing the electrolyte, voltage and temperature in the synthesis process. In this article, through the analysis of current production curve in the process of comparison of the anodic alumina template system and realize the current common microscope to control and monitor the size of the template. The relationship between current and voltage and pore size is studied, so as to realize the precise preparation of anodic aluminum oxide template based on current-controlled method. [ABSTRACT FROM PUBLISHER]

Abstract: A high quality anodic aluminum oxide (AAO) template with ordered apertures about 50–80nm was fabricated by anodizing aluminum in electrolytes through a two-step method, and silver nanowires with diameters from 40nm to 70nm were prepared on this AAO template by magnetron sputtering. On the glass covered with silver nanowires, high quality surface enhanced Raman scattering (SERS) spectra of sudan II (C18H16N2O) with enhancement factors of 105 were obtained. And comparison of SERS spectra on silver nanowires with the SERS spectra of silver colloids indicates that main enhanced mode is lightning rod effect of nanorods on the Sudan II/silver nanowires system. [Copyright &y& Elsevier]

Abstract: High quality ZnO epilayers (χ min ∼10%) were prepared on Al2O3 (0001) substrates at a temperature of 750°C by pulsed laser deposition (PLD) with oxygen pressure of 0.015, 0.15, 1.5, and 15Pa. The best crystalline quality and strongest intensity of UV photoluminescence were observed on ZnO layer with oxygen pressure of 15Pa. It is probable due to the higher oxygen pressure lessens oxygen deficiency in the film. The tetragonal distortion e T, which is caused by elastic strain in the epilayer, was determined by Rutherford backscattering/channeling. It reduces as a whole (from 0.93 to 0.65%) with the increase of oxygen pressure from 0.015 to 15Pa and the excitonic transition energy simultaneously shows a weak blue shift. [Copyright &y& Elsevier]

Abstract: Vertical-aligned Ag nanoflake arrays are fabricated on the surface of an anodic aluminum oxide (AAO) template under a hydrothermal condition for the first time. The porous surface of AAO templates and the precursor solution may play key roles in the process of fabricating Ag nanoflakes. The rim of pores can provide many active sites for nucleation and growth, and then nanoflake arrays gradually form through self-assembly of Ag on the surface of AAO membranes. The product is characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and a growth mechanism of nanoflake is deduced. This work demonstrates that it is possible to make ordered nanoarrays without dissolving templates using the hydrothermal method, and this interesting Ag nanoflake arrays may provide a wider range of nanoscale applications. [Copyright &y& Elsevier]

Abstract: This paper describes a new approach to the synthesis of Ag nanorods. A solvothermal method was used to make Ag nanoparticles inside anodic aluminum oxide (AAO) templates. The nanoparticles were then annealed at 300°C to produce Ag nanorods. The size of AAO templates, which is focused on in this study, would determine the diameter of Ag nanorods. The product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In this study, a nanorod growth mechanism is deduced, and understanding of the growth of nanorods inside AAO templates is furthered. This work demonstrates that it is possible to make crystalline nanorods that the size can be varied. [Copyright &y& Elsevier]