Fabrication of Superconducting Nanowires Using the Template Method

The fabrication and characterization of superconducting nanowires fabricated by the anodic aluminium oxide (AAO) template technique has been reviewed. This templating method was applied to conventional metallic superconductors, as well as to several high-temperature superconductors (HTSc). For filling the templates with superconducting material, several different techniques have been applied in the literature, including electrodeposition, sol-gel techniques, sputtering, and melting. Here, we discuss the various superconducting materials employed and the results obtained. The arising problems in the fabrication process and the difficulties concerning the separation of the nanowires from the templates are pointed out in detail. Furthermore, we compare HTSc nanowires prepared by AAO templating and electrospinning with each other, and give an outlook to further research directions.

Controllable fabrication of polymeric nanowires by NIL technique and self-assembled AAO template for SERS application

A controllable strategy to fabricate the polymeric nanowires with high throughput and low cost is developed by using the thermal nanoimprint lithography (NIL) technique and self-assembled anodic aluminum oxide (AAO) template. The length of polymeric nanowires can be controlled by adjusting the duration of thermal NIL. A fill mechanism of thermoplastic intermediate polymer stamp (IPS) polymer pressed into the AAO nanopores is closely studied. The as-prepared IPS polymeric nanowire-based Surface-Enhanced Raman Scattering (SERS)-active substrate exhibits a remarkable reproducibility. The effective adsorption of the R6G as probe molecule near to hotspots generated at 3D vertically aligned polymeric nanowire SERS active substrates shows extraordinary enhancement of Raman signal with an enhancement factor (EF) of 105–106. The present strategy is of great guiding significance to broaden the use of thermal NIL technique and AAO template for the fabrication of other nanomaterials, especially for the flexible and transparent polymer-based nanomaterials.

Magnetic anisotropy and phohotoluminescence properties of amorphous CexFeyOn nanowire arrays

Amorphous Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowire arrays with diameters about 100 nm were fabricated in porous anodic aluminum oxide (AAO) template channels by chemical co-precipitation assisted by suction filtration. Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowire arrays have distinct magnetic anisotropy behavior, and the axis parallel to the nanowire is magnetically “easy.” The magnetic properties of Ce[Formula: see text]Mn[Formula: see text]O[Formula: see text] and Ce[Formula: see text]Fe[Formula: see text]Mn[Formula: see text]O[Formula: see text] nanowire arrays were investigated to compare with Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowire arrays. The fluorescence spectra of Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowires arrays mixed with Eu, Tb, Sm showed that their emission intensity displays regular change with the increase of the mole fraction of mixture. The emission intensity reached maximum with increasing of Eu or Sm-mixing from 2 mol% to 10 mol% at 591 nm, 709 nm or 607 nm, then decreased gradually. However, there is no obvious influence to fluorescence of Tb mixed Ce[Formula: see text]Fe[Formula: see text]O[Formula: see text] nanowire arrays, only one visible weak emission peak is present at 486 nm.

Structure and optical properties of porous SiC film grown by magnetron sputtering on porous anodic aluminium oxide template

Porous fluorescent SiC films were deposited by magnetron sputtering (MS) using porous anodic aluminium oxide (AAO) template. In the first step AAO was carefully placed on the Si substrate and then coated with SiC film using magnetron sputtering at the deposition temperature of 873K for different times. The pore diameter, pore spacing and thickness of the double pass porous AAO template were 300, 450 and 500 nm, respectively. The SiC film deposited for 60min showed macroporous structure with the pore size of 200 to 250 nm and pore spacing of 450 nm. The photoluminescence (PL) spectrum of the porous SiC film ranged from 400 to 700 nm. The band gap of SiC is 2.305 eV, and the phonon energy of phonon participating in PL of SiC is estimated at 0.075 eV. The source of phonon participating in PL of SiC may be from phonon scattering of silica/SiC interface in porous SiC film. The porous AAO template assisted magnetron sputtering is a promising technical processing for the fabrication of macroporous fluorescent SiC film.

Growth of less than 20 nm SnO Nanowire Using AAO Template for Gas Sensing

Large-scale stannous oxide (SnO) nanowires were synthesized via a template and catalyst-free thermal oxidation process. After annealing Sn nanowires embedded AAO template in atmosphere, we observed a large scale of SnO nanowires. SnO nanowires were first prepared via the electrochemical deposition and an oxidization method based on an AAO template. The preparation of SnO nanowires use aluminum sheet (purity 99.999%) and then two-step anodization procedure to obtain raw alumina mold. Finally, transparent alumina mold (AAO template) were obtained by the reaming, soaking with phosphoric acid for 20 minutes and a stripping process. We get a pore size of < 20 nm transparent alumina mold. In order to electroplating needs, we produce platinum film on the bottom surface of AAO template by using sputtering method as the electrode of electroplating deposition. The structure was characterized by X-ray diffraction (XRD). High resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM) with x-ray energy dispersive spectrometer (EDS) was used to observe the morphology. The EDS spectrum showed that components of the materials are Sn and O. FE-SEM results show the synthesized SnO nanowires to have an approximate length of ~ 10 - 20 μm with a highly aspect ratio > 500. SnO nanowires with an Sn/O atomic ratio of ~ 1 : 1 were observed from EDS. The crystal structure of SnO nanowires showed that all the peaks within the spectra can be indexed to SnO with a tetragonal structure. This studies may lead to the use of the 1D structure nanowires into electronic nanodevices and/or sensors, thus leading to nanobased functional structures.