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1.
Template synthesis of Y-junction metal nanowires 总被引:2,自引:0,他引:2
T. Gao G. Meng J. Zhang S. Sun L. Zhang 《Applied Physics A: Materials Science & Processing》2002,74(3):403-406
Template synthesis of large-scale Y-junction metal nanowires is reported. In this approach, a Y-shaped nanochannel porous
anodic alumina (PAA) template is prepared by using a two-step anodization of aluminum in which the metal of interest, such
as copper, is electrodeposited to form the Y-junction metal nanowires. The synthesis method presented here is simple and versatile.
This method can be extended to the preparation of other Y-junction nanowires with desirable composition and shows great promise
for the development of nanoelectronics.
Received: 10 September 2001 / Accepted: 20 November 2001 / Published online: 23 January 2002 相似文献
2.
Copper nanowire arrays for infrared polarizer 总被引:10,自引:0,他引:10
Y.T. Pang G.W. Meng Y. Zhang Q. Fang L.D. Zhang 《Applied Physics A: Materials Science & Processing》2003,76(4):533-536
A micropolarizer of copper nanowire arrays within anodic alumina membrane (AAM) was fabricated by anodization of pure Al foil
and electrodeposition of Cu, respectively. X-ray diffraction, scanning electron microscopy and transmission electron microscopy
investigations reveal that the ordered Cu nanowires are essentially single crystal, and have an average diameter of 90 nm.
Spectrophotometer measurements show that the copper nanowire arrays embedded in AAM can only transmit polarized light vertical
to the wires. An extinction ratio of 24 to 32 dB and an average insertion loss of 0.5 dB in the wavelength range of 1 to 2.2 μm
were obtained, respectively. Therefore Cu nanowire/AAM can be used as a wire grid type micropolarizer.
Received: 28 January 2002 / Accepted:17 May 2002 / Published online: 22 November 2002
RID="*"
ID="*"Corresponding author. Fax: +86-551/559-1434, E-mail: ytpang@263.net 相似文献
3.
Electrochemical synthesis of ordered CdTe nanowire arrays 总被引:1,自引:0,他引:1
A.W. Zhao G.W. Meng L.D. Zhang T. Gao S.H. Sun Y.T. Pang 《Applied Physics A: Materials Science & Processing》2003,76(4):537-539
Semiconductor CdTe nanowire arrays embedded in the nanochannels of the porous anodic alumina (PAA) template have been prepared
by using a potentiostatic electrochemical deposition method. The morphology and structure of the CdTe nanowire arrays have
been characterized by X-ray powder diffraction, transmission electron microscopy, and high-resolution transmission electron
microscopy. It is found that the CdTe nanowires with diameters and lengths of about 60 nm are single-crystalline with cubic
phase structure, uniformly and continuously embedded in the nanochannels of the PAA template. X-ray energy-dispersion analysis
and X-ray photoelectron spectroscopy analysis indicate that stoichiometric CdTe was formed. The growth mechanism of the CdTe
nanowires is also discussed.
Received: 11 June 2002 / Accepted: 2 July 2002 / Published online: 8 January 2003
RID="*"
ID="*"Corresponding author. Fax: +86-551/559-1434, E-mail: aiwuzhao@yahoo.com.cn 相似文献
4.
Fabrication, morphology and structural characterization of ordered single-crystal Ag nanowires 总被引:1,自引:0,他引:1
J. Zhang X. Wang X. Peng L. Zhang 《Applied Physics A: Materials Science & Processing》2002,75(4):485-488
Highly aligned Ag nanowires have been synthesized by dc electrodeposition within a hexagonal close-packed nanochannel anodic
aluminum oxide template. The pore diameter varies from 20 nm to 50 nm depending on the anodization voltage and temperature
for the two types of aqueous solutions, sulphuric and oxalic acids, respectively. The size and morphology of the Ag nanowire
arrays were measured by scanning electron microscopy and transmission electron microscopy. The images indicate that the highly
aligned Ag nanowires grow in the uniform nanochannels of the anodic alumina template and that the size of the nanowires depends
on the size of the nanochannels. X-ray diffraction, selected area electron diffraction pattern and high-resolution transmission
electron microscopy images show that the Ag nanowires are single-crystal. The temperature coefficient of resistivity (temperature
range from 4.2 K to 300 K) of the Ag nanowire arrays decreases with decreasing diameter of the nanowires.
Received: 5 November 2001 / Revised version: 12 March 2002 / Published online: 6 June 2002 相似文献
5.
6.
A. Tilke L. Pescini R.H. Blick H. Lorenz J.P. Kotthaus 《Applied Physics A: Materials Science & Processing》2000,71(4):357-365
We present a brief overview on different realizations of single-electron devices fabricated in silicon-on-insulator films.
Lateral structuring of highly doped silicon films allows us to observe quasi-metallic Coulomb blockade oscillations in shrunken
wires where no quantum dot structure is geometrically defined. Embedding quantum dot structures into the inversion channel
of a silicon-on-insulator field-effect transistor Coulomb blockade up to 300 K is observed. In contrast to the quasi-metallic
structures, in these devices the influence of the quantum mechanical level spacing inside the dot becomes visible. Suspending
highly doped silicon nanostructures leads to a novel kind of Coulomb blockade devices allowing both high-power application
as well as the study of electron–phonon interaction.
Received: 14 April 2000 / Accepted: 17 April 2000 / Published online: 6 September 2000 相似文献
7.
T. Li Q. Lou J. Dong Y. Wei J. Liu 《Applied Physics A: Materials Science & Processing》2000,71(3):271-276
Numerical calculations based on a thermal model were presented, which describe the process of target heating and ablation
of cobalt during irradiation by 30-ns laser pulses at 308 nm. The attenuation of laser by vapor has been taken into account
in this model. As results of the calculations, the temperature distribution beneath the target surface and the temporal evolution
of surface temperature were given. The dependence of ablation rate on laser fluence was also studied based on this model.
The surface ablation of cobalt with pulsed excimer laser was investigated experimentally. Our model considering proper vapor
attenuation has shown to be in good agreement with the experimental results.
Received: 20 January 2000 / Accepted: 13 March 2000 / Published online: 5 July 2000 相似文献
8.
J.Y. Li X.L. Chen Z.Y. Qiao Y.G. Cao M. He T. Xu 《Applied Physics A: Materials Science & Processing》2000,71(3):349-350
Self-aligned GaN nanowire quasi-arrays were synthesized on MgO crystal through a simple gas reaction method. They were characterized
by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray (EDX) spectroscopy
and high-resolution transmission electron microscopy (HRTEM). FE-SEMimages showed that the product consisted of quasi-arrays
of nanowires. XRD, EDX and HRTEM indicated that the nanowires were wurtzite GaN single crystals.
Received: 19 June 2000 / Accepted: 21 June 2000 / Published online: 9 August 2000 相似文献
9.
Highly oriented GaN nanowire arrays have been achieved by the catalytic reaction of gallium with ammonium. The resulting materials
were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (SEM), energy dispersive X-ray
spectroscopy (EDS), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). SEM images show
that the resulting materials are nanowire arrays with a uniform length of about 10 μm. XRD, EDS, TEM and SAED indicate that
the nanowire arrays are single-crystal hexagonal GaN with a wurtzite structure. They have diameters of 10 to 20 nm.
Received: 2 October 2002 / Accepted: 7 October 2002 / Published online: 17 December 2002
RID="*"
ID="*"Corresponding author. E-mail: wwwangjc@sina.com 相似文献
10.
G.W. Meng X.S. Peng Y.W. Wang C.Z. Wang X.F. Wang L.D. Zhang 《Applied Physics A: Materials Science & Processing》2003,76(1):119-121
Aligned SiOx nanowire arrays standing on a Si substrate were successfully synthesized using a simple method by heating a single-crystalline
Si slice covered with SiO2 nanoparticles at 1000 °C in a flowing Ar atmosphere. The SiOx nanowire arrays were characterized by scanning electron microscopy and transmission electron microscopy. The SiOx nanowires become progressively thinner from bottom to top. The formation process of the SiOx nanowire arrays is closely related to a vapor–solid mechanism. Room-temperature photoluminescence measurements under excitation
at 260 nm showed that the SiOx nanowire arrays had a strong blue–green emission at 500 nm (about 2.5 eV), which may be related to oxygen defects.
Received: 29 April 2002 / Accepted: 30 April 2002 / Published online: 10 September 2002
RID="*"
ID="*"Corresponding author. Fax: +86-551-559-1434, E-mail: gwmeng@mail.issp.ac.cn 相似文献
11.
T. Li Q. Lou J. Dong Y. Wei J. Liu 《Applied Physics A: Materials Science & Processing》2001,73(3):391-397
Surface ablation of cobalt-cemented tungsten carbide hard metal has been carried out in this work using a 308 nm, 20 ns XeCl
excimer laser. Surface microphotography and XRD, as well as an electron probe have been used to investigate the transformation
of phase and microstructure as a function of the pulse-number of laser shots at a laser fluence of 2.5 J/cm2. The experimental results show that the microstructure of cemented tungsten carbide is transformed from the original polygonal
grains of size 3 μm to interlaced large, long grains with an increase in the number of laser shots up to 300, and finally
to gross grains of size 10 μm with clear grain boundaries after 700 shots of laser irradiation. The crystalline structure
of the irradiated area is partly transformed from the original WC to βWC1-x, then to αW2C and CW3, and finally to W crystal. It is suggested that the undulating ‘hill–valley’ morphology may be the result of selective removal
of cobalt binder from the surface layer of the hard metal. The formation of non-stoichiometric tungsten carbide may result
from the escape of elemental carbon due to accumulated heating of the surface by pulsed laser irradiation.
Received: 13 July 2000 / Accepted: 27 October 2000 / Published online: 10 January 2001 相似文献
12.
We have observed hysteresis loops in current transport in a GaAs metal–semiconductor–metal diode containing InAs quantum dots.
The dots in our structure are directly embedded under the GaAs–metal interface. The charging and discharging of electrons
in the dots modulate the current and produce hysteresis. These processes are controlled by the applied voltages. The dots
are charged by forward current flowing through the structure. The discharging of the electrons is dominated by the tunneling
process under high reverse bias. The modulated currents are well fitted with an electron-trapping model considering both the
ground states and the excited states of the quantum dots.
Received: 5 October 2000 / Accepted: 12 December 2000 / Published online: 23 May 2001 相似文献
13.
S.H. Sun G.W. Meng Y.W. Wang T. Gao M.G. Zhang Y.T. Tian X.S. Peng L.D. Zhang 《Applied Physics A: Materials Science & Processing》2003,76(2):287-289
Tin dioxide (SnO2) nanobelts have been successfully synthesized in bulk quantity by a simple and low-cost process based on the thermal evaporation
of tin powders at 800 °C. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations reveal
that the nanobelts are uniform, with lengths from several-hundred micrometers to a few millimeters, widths of 60 to 250 nm
and thicknesses of 10 to 30 nm. X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and selected-area electron
diffraction analysis (SAED) indicate that the nanobelts are tetragonal rutile structure of SnO2. The SnO2 nanobelts grow via a vapor–solid (VS) process.
Received: 3 June 2002 / Accepted: 10 June 2002 / Published online: 10 September 2002
RID="*"
ID="*"Corresponding author. Fax: +86-551/559-1434, E-mail: gwmeng@mail.issp.ac.cn 相似文献
14.
K. Suenaga F. Willaime A. Loiseau C. Colliex 《Applied Physics A: Materials Science & Processing》1999,68(3):301-308
2 bonds attests for the presence of ordered BN domains and of carbon domains; (ii) the elemental profiles show that BN layers
and carbon layers are immiscible with a radial organisation into two to five domains; and (iii) the sets of layers at free
surfaces – including the inner surfaces of tubes – are always made of carbon. The origin of this chemical organisation, which
is most likely obtained during the growth, is discussed. For the hafnium-boride metallic particles coated by C/BN envelopes,
a model based on the solidification from the outside to the inside of isolated liquid-like droplets is proposed: the carbon
phase solidifies first according to theoretical phase diagrams, and forms the outer shells. For the tubes, a directional eutectic
solidification process is shown to account for the observed C/BN/C sequence, in a vapour–liquid–solid scheme, with an hafnium-rich
liquid-like particle at the tip of the tube.
Received: 26 November 1998 / Accepted: 14 January 1999 相似文献
15.
S.-H. Jung M.-R. Kim S.-H. Jeong S.-U. Kim O.-J. Lee K.-H. Lee J.-H. Suh C.-K. Park 《Applied Physics A: Materials Science & Processing》2003,76(2):285-286
Synthesis of multi-walled carbon nanotubes (MWNTs) by arc discharge in liquid nitrogen is reported. As liquid nitrogen substituted
both vacuum and cooling systems, high-quality MWNTs were produced at a low cost. The content of the MWNTs can be as high as
70% of the reaction product. Auger-spectroscopy analysis revealed that no nitrogen is incorporated in the MWNTs. This method
can be an economical route for the mass production of highly crystalline MWNTs.
Received: 5 July 2002 / Accepted: 8 July 2002 / Published online: 10 September 2002
RID="*"
ID="*"Corresponding author. Fax: +82-54/279-8298, E-mail: ce20047@postech.ac.kr 相似文献
16.
Y. Li C. Tan Y. Xia J. Zhang C. Xue H. Xu P. Liu 《Applied Physics A: Materials Science & Processing》2000,71(6):689-693
Si crystals were implanted with 2.0- MeV Er+ at the doses of 5×1012 ions/cm2, 1×1014 ions/cm2, 5×1014ions/cm2, 1×1015 ions/cm2 and 2.5×1015 ions/cm2. Conventional furnace thermal annealing was carried out in the temperature range from 600 °C to 1150 °C. The depth distribution
of Er, associated damage profiles and annealing behavioar were investigated using the Rutherford backscattering spectrometry
and channelling (RBS/C) technique. A proper convolution program was used to extract the distribution of Er from the experimental
RBS spectrum. The obtained distribution parameters, projected range Rp, projected range straggling ΔRp and skewness SK were compared with those of TRIM96 calculation.The experimental Rp and SK values agree well with the simulated values, while the experimental ΔRp is larger than TRIM 96 simulated value by a factor of 18%. The damage profile of silicon crystal induced by 2.0-MeV Er+ at a dose of 1×1014 ions/cm2 was extracted using the multiple-scattering dechannelling model based on Feldman’s method, which is in a good agreement with
the TRIM96 calculation. For the samples with dose of 5×1014 ions/cm2 and more, an abnormal annealing behavioar was found and a qualitative explaination has been given.
Received: 11 October 1999 / Accepted: 28 March 2000 / Published online: 5 July 2000 相似文献
17.
X.S. Peng Y.W. Wang J. Zhang X.F. Wang L.X. Zhao G.W. Meng L.D. Zhang 《Applied Physics A: Materials Science & Processing》2002,74(3):437-439
In2O3 nanowires have been successfully fabricated on a large scale from indium particles by thermal evaporation at 1030 °C. The
as-synthesized products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission
electron microscopy (TEM). SEM and TEM images show that these nanowires are uniform with diameters of about 60–120 nm and
lengths of about 15–25 μm. XRD and selected-area electron diffraction analysis together indicate that these In2O3 nanowires crystallize in a cubic structure of the bixbyite Mn2O3 (I) type (also called the C-type rare-earth oxide structure). The growth mechanism of these nanowires is also discussed.
Received: 29 June 2001 / Accepted: 28 September 2001 / Published online: 20 December 2001 相似文献
18.
J.H. Chen Z.P. Huang D.Z. Wang S.X. Yang J.G. Wen Z.F. Ren 《Applied Physics A: Materials Science & Processing》2001,73(2):129-131
Polypyrrole/carbon nanotube nanoscale composites were successfully fabricated by electrochemical deposition of polypyrrole
over each of the carbon nanotubes in well-aligned large arrays. The thickness of the polypyrrole coating can be easily controlled
by the value of the film-formation charge. For both thin (low film-formation charge) and thick (high film-formation charge)
films, the polypyrrole coating on the surface of each nanotube is very uniform throughout the entire length, as observed by
transmission electron microscopy.
Received: 2 May 2001 / Accepted: 4 May 2001 / Published online: 20 June 2001 相似文献
19.
In this contribution, the blending of nano-titanium dioxide (TiO2) and polylactide (PLA) nanofibers has been adopted as a new nanomaterial to facilitate the biorecognition of an anticancer drug daunorubicin. Our observations demonstrate that upon application of the nano-TiO2-PLA polymer nanocomposites, the drug molecules could be readily self-assembled on the surface of the new nanocomposites so that considerably enhanced detection sensitivity for the DNA binding behavior could be observed for the relative biorecognition. These results may also imply some potential valuable application of the blending of nano-TiO2 and PLA nanofibers as a kind of drug carriers in view of the respective good biocompatibility and large surface area of the new nanocomposites. 相似文献
20.
Ablation rates of aluminum and stainless steel are studied as a function of fluence, hole depth, pulse duration and ambient
pressure (air vs vacuum). We find a weak rate dependence on pulse duration from 150 fs to 500 ps, and a strong rate dependence
on hole depth due to surface roughness. Machining in air plays an important role in deep holes, but has a weaker influence
on initial surface ablation rates. Oxidation greatly reduces drilling rates for deep holes in aluminum.
Received: 26 December 2001 / Accepted: 9 July 2002 / Published online: 4 November 2002
RID="*"
ID="*"Corresponding author. Fax: +1-925/422-5537, E-mail: stuart3@llnl.gov 相似文献