A Method for Forming Very Small Diameter Wires
01 May 1970-Review of Scientific Instruments (American Institute of PhysicsAIP)-Vol. 41, Iss: 5, pp 772-774
About: This article is published in Review of Scientific Instruments.The article was published on 1970-05-01. It has received 252 citations till now.
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TL;DR: A highly ordered metal nanohole array (platinum and gold) was fabricated by a two-step replication of the honeycomb structure of anodic porous alumina that showed a notable color change compared with bulk gold.
Abstract: A highly ordered metal nanohole array (platinum and gold) was fabricated by a two-step replication of the honeycomb structure of anodic porous alumina. Preparation of the negative porous structure of porous alumina followed by the formation of the positive structure with metal resulted in a honeycomb metallic structure. The metal hole array of the film has a uniform, closely packed honeycomb structure approximately 70 nanometers in diameter and from 1 to 3 micrometers thick. Because of its textured surface, the metal hole array of gold showed a notable color change compared with bulk gold.
4,892 citations
TL;DR: A relatively new method for preparing nanomaterials, membrane-based synthesis, is reviewed, which entails synthesis of the desired material within the pores of a nanoporous membrane.
Abstract: Materials with nanoscopic dimensions not only have potential technological applications in areas such as device technology and drug delivery but also are of fundamental interest in that the properties of a material can change in this regime of transition between the bulk and molecular scales. In this article, a relatively new method for preparing nanomaterials, membrane-based synthesis, is reviewed. This method entails synthesis of the desired material within the pores of a nanoporous membrane. Because the membranes used contain cylindrical pores of uniform diameter, monodisperse nanocylinders of the desired material, whose dimensions can be carefully controlled, are obtained. This "template" method has been used to prepare polymers, metals, semiconductors, and other materials on a nanoscopic scale.
3,887 citations
TL;DR: In this paper, the template method is used to synthesize nanotubules and fibrils of polymers, metals, semiconductors, carbons, and other materials.
Abstract: This paper reviews a relatively new method for preparing nanomaterials: membrane-based synthesis. This method entails the synthesis of the desired material within the pores of a nanoporous membrane. Because the membranes employed contain cylindrical pores of uniform diameter, monodisperse nanocylinders of the desired material, whose dimensions can be carefully controlled, are obtained. These nanocylinders may be either hollow (a tubule) or solid (a fibril or nanowire). We call this approach the “template” method because the pores in the nanoporous membranes are used as templates for forming the desired material. This template method is a very general approach; it has been used to prepare nanotubules and fibrils of polymers, metals, semiconductors, carbons, and other materials.
1,419 citations
TL;DR: Arrays of ferromagnetic nickel and cobalt nanowires have been fabricated by electrochemical deposition of the metals into templates with nanometer-sized pores prepared by nuclear track etching, displaying distinctive characteristics because of their one-dimensional microstructure.
Abstract: Arrays of ferromagnetic nickel and cobalt nanowires have been fabricated by electrochemical deposition of the metals into templates with nanometer-sized pores prepared by nuclear track etching. These systems display distinctive characteristics because of their one-dimensional microstructure. The preferred magnetization direction is perpendicular to the film plane. Enhanced coercivities as high as 680 oersteds and remnant magnetization up to 90 percent have also been observed.
1,146 citations
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References
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TL;DR: In this article, a study of the effect of etching on particle tracks in various silicate minerals is reported as a function of the etching reagent, etching temperature, and etching time.
Abstract: When a heavy charged particle such as a fission fragment traverses certain materials it leaves a trail of radiation damage which shows up as a track when a sample is viewed by transmission electron microscopy. If a sample of a silicate mineral containing such tracks is immersed in a suitable reagent such as hydrofluoric acid it has been found that the tracks are very selectively attacked. Fine hollow channels are formed along the particle paths while the rest of the material is untouched. A study of this effect in various silicate minerals is reported as a function of etching reagent, etching temperature, and etching time. The minimum width of the etched channels is considerably less than the apparent widths of the tracks prior to etching. It is concluded that the track images result in large part from elastic strains surrounding a damaged core. The etching effect also serves to ``develop'' and ``fix'' particle tracks and hence increases the usefulness of silicate minerals as particle detectors.
227 citations
TL;DR: In this paper, track registration in muscovite mica, Lexan polycarbonate, and cellulose nitrate was shown to be consistent with the ion explosion spike mechanism for track formation.
Abstract: Dielectric track detectors have a sharp threshold for track registration that depends on the atomic number and the energy of the bombarding particles. New data on track registration in muscovite mica, Lexan polycarbonate, and cellulose nitrate contradict the previously proposed empirical criterion that tracks are formed if the total rate of energy loss exceeds a critical value that is characteristic of the solid. In contrast, the ion explosion spike mechanism for track formation predicts that a solid will record tracks if the rate of primary ionization exceeds a critical rate for that solid. All the known experimental measurements are consistent with this criterion.
179 citations
TL;DR: In this paper, it is shown that fission fragments from Cf252 leave damage trails in glass which may be etched to give conical pits, which can be used to display the paths of heavy particles in a great many non-crystalline materials.
Abstract: Heavily ionizing particles passing through crystalline solids may produce trails of damage which can be seen either directly by electron microscopy or indirectly, by means of preferential chemical dissolution of the damaged material. Where both methods have been used, it has been shown that the method of chemical attack is the more sensitive. Here it is reported that this method of revealing irradiation effects is able also to display the paths of heavy particles in a great many noncrystalline materials, in this instance glass. It is shown that fission fragments from Cf252 leave damage trails in glass which may be etched to give conical pits. In some glasses the cone angles are small, so that the direction taken by the moving particles may be followed. Fission tracks can also be revealed in certain glasses by preferential precipitation of a metal such as silver along the damaged regions. This method has the advantage that a track does not have to intersect a free surface to be revealed.
103 citations
92 citations
TL;DR: In this article, the normal state reactive and resistive skin depths of very pure polycrystalline tin and indium have been measured as a function of frequency for frequencies between 7 and 20 000 cps.
Abstract: The normal-state reactive and resistive skin depths of very pure polycrystalline tin and indium have been measured as a function of frequency for frequencies between 7 and 20 000 cps. Measurements were made at liquid-helium temperatures, using specimens in the form of flat plates with a thickness of 1 mm. The free-electron anomalous-skin-effect theory of Reuter and Sondheimer was used to extrapolate the data to infinite frequency, and thus to obtain skin depths appropriate to the extreme anomalous limit. Analysis of the data based on the free-electron model and assuming diffuse electron scattering at the metal surfaces yields the values ${(\frac{\ensuremath{\sigma}}{l})}_{\mathrm{Sn}}=(6.9\ifmmode\pm\else\textpm\fi{}1.5)\ifmmode\times\else\texttimes\fi{}{10}^{10}$ ${\mathrm{\ensuremath{\Omega}}}^{\ensuremath{-}1}$ ${\mathrm{cm}}^{\ensuremath{-}2}$ and ${(\frac{\ensuremath{\sigma}}{l})}_{\mathrm{In}}=(9.0\ifmmode\pm\else\textpm\fi{}1.6)\ifmmode\times\else\texttimes\fi{}{10}^{10}$ ${\mathrm{\ensuremath{\Omega}}}^{\ensuremath{-}1}$ ${\mathrm{cm}}^{\ensuremath{-}2}$. The skin depths are estimated to deviate from their anomalous limits by approximately 2% at a frequency of 1 Mc/sec.
23 citations