共查询到20条相似文献,搜索用时 15 毫秒
1.
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
2.
J.K. Jian X.L. Chen W.J. Wang L. Dai Y.P. Xu 《Applied Physics A: Materials Science & Processing》2003,76(2):291-294
Single-crystalline SnO2 nanowires, nanobelts and nanodendrites were synthesized by a simple gas-reaction route on a large scale at 900 °C. They were
characterized by means of X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive
X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). FE-SEM images
showed that the products consisted of nanowires, nanobelts and nanodendrites that represent a novel morphology reported for
the first time. XRD, SAED and EDS indicated that they were single-crystalline tetragonal SnO2. The influence of experimental conditions on the morphologies of the products is discussed.
Received: 3 June 2002 / Accepted: 10 June 2002 / Published online: 10 September 2002
RID="*"
ID="*"Corresponding author. Fax: 86-10/82649531, E-mail: xlchen@aphy.iphy.ac.cn 相似文献
3.
L.X. Zhao G.W. Meng X.S. Peng X.Y. Zhang L.D. Zhang 《Applied Physics A: Materials Science & Processing》2002,74(4):587-590
Large quantities of gallium nitride (GaN) nanorods have been synthesized via direct reaction of metallic gallium vapor with
flowing ammonia at 970 °C in a quartz tube. The nanorods have been confirmed as crystalline wurzite GaN by powder X-ray diffraction,
selected-area electron diffraction and X-ray photoelectron spectrometry. Transmission electron microscopy and scanning electron
microscopy reveal that the nanorods are straight and uniform, with diameters ranging from 40 nm to 150 nm and lengths up to
hundreds of micrometers. The growth mechanism is discussed briefly. Photoluminescence measurements on bulk GaN nanorods at
room temperature show two strong peaks at 377 nm (3.28 eV) and 360 nm (3.44 eV) attributed to the zero-phonon donor-acceptor
pair transition and the donor-bound exciton, respectively.
Received: 19 April 2001 / Accepted: 10 May 2001 / Published online: 20 June 2001 相似文献
4.
S.H. Sun G.W. Meng T. Gao M.G. Zhang Y.T. Tian X.S. Peng Y.X. Jin L.D. Zhang 《Applied Physics A: Materials Science & Processing》2003,76(6):999-1002
Novel micrometer-sized Si-Sn-O structures with SiO2 nanowires (SiONWs) growing from their surfaces have been achieved at about 980 °C on Si (111) wafer catalyzed by Sn vapor
generated from Sn powders. The Si wafer itself served as a silicon source in the reaction. The micrometer-sized structures,
with diameters of several micrometers to several tens of micrometers consisted of Sn, Si and O. The amorphous SiONWs growing
from the surface of the micrometer-sized structures were smooth, with diameters about 120 nm and with a composition close
to that of SiO2. The growth mechanism of these novel structures is discussed briefly.
Received: 30 July 2002 / Accepted: 18 September 2002 / Published online: 4 December 2002
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ID="*"Corresponding author. Fax: +86-551/5591434, E-mail: shsuncn@hotmail.com 相似文献
5.
Ion synthesis and laser annealing of Cu nanoparticles in Al2O3 总被引:1,自引:0,他引:1
A.L. Stepanov V.N. Popok D.E. Hole I.B. Khaibullin 《Applied Physics A: Materials Science & Processing》2002,74(3):441-446
Al2O3 samples with Cu nanoparticles, synthesised by ion implantation at 40 keV with a dose of 1×1017 ion/cm2 and a current density from 2.5 to 12.5 μA/cm2, were annealed using ten pulses from a KrF excimer laser with a single pulse fluence of 0.3 J/cm2. The copper depth distribution, formation and modification of metal nanoparticles under the ion implantation and laser treatment
were studied by Rutherford backscattering (RBS), energy dispersive X-ray (EDX) analysis, atomic force microscopy (AFM) and
optical spectroscopy. It was found that laser annealing leads to a reduction in the nanoparticle size without diffusion of
metal atoms into the bulk. The change in particle size and the possibility for oxidation of the copper particles are examined
in the framework of Mie theory. Calculations presented show that under excimer laser treatment, Cu nanoparticles are more
likely to be reduced in size than to undergo oxidation.
Received: 19 April 2001 / Accepted: 7 November 2001 / Published online: 23 January 2002 相似文献
6.
Strong green luminescence of Ni2+-doped ZnS nanocrystals 总被引:1,自引:0,他引:1
P. Yang M. Lü D. Xü D. Yuan J. Chang G. Zhou M. Pan 《Applied Physics A: Materials Science & Processing》2002,74(2):257-259
ZnS nanoparticles doped with Ni2+ have been obtained by chemical co-precipitation from homogeneous solutions of zinc and nickel salt compounds, with S2- as precipitating anion, formed by decomposition of thioacetamide (TAA). The average size of particles doped with different
mole ratios, estimated from the Debye–Scherrer formula, is about 2–2.5 nm. The nanoparticles could be doped with nickel during
synthesis without altering the X-ray diffraction pattern. A Hitachi M-850 fluorescence spectrophotometer reveals the emission
spectra of samples. The absorption spectra show that the excitation spectra of Ni-doped ZnS nanocrystallites are almost the
same as those of pure ZnS nanocrystallites (λex=308–310 nm). Because a Ni2+ luminescent center is formed in ZnS nanocrystallites, the photoluminescence intensity increases with the amount of ZnS nanoparticles
doped with Ni2+. Stronger and stable green-light emission (520 nm) (its intensity is about two times that of pure ZnS nanoparticles) has
been observed from ZnS nanoparticles doped with Ni2+.
Received: 18 December 2000 / Accepted: 17 March 2001 / Published online: 20 June 2001 相似文献
7.
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
8.
T. Gao G.W. Meng J. Zhang Y.W. Wang C.H. Liang J.C. Fan L.D. Zhang 《Applied Physics A: Materials Science & Processing》2001,73(2):251-254
Cu nanowire arrays have been synthesized using potentiostatic electrodeposition within the confined nanochannels of a porous
anodic alumina membrane. The Cu nanowire arrays and the individual nanowires have been characterized using SEM, TEM, SAED,
HREM and XRD. Investigation results reveal that the Cu nanowire arrays having high wire packing densities are highly ordered
over large areas. The individual Cu nanowires (diameter ∼60 nm) were single-crystal and found to be dense and continuous with
uniform diameters throughout their entire length. An optimum ECD condition (at lower overpotentials) for the synthesis of
single-crystal Cu nanowires was also discussed.
Received: 19 April 2001 / Accepted: 28 April 2001 / Published online: 20 June 2001 相似文献
9.
Novel porous ZnO nanobelts were successfully synthesized by heating layered basic zinc acetate (LBZA) nanobelts in the air. The precursor of LBZA nanobelts consisted of a lamellar structure with two interlayer distances of 1.325 and 0.99 nm were prepared using a low-temperature, solution-based method. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and infrared spectroscopy are used to characterize the as-products. PL measurements show that the porous ZnO nanobelts have strong ultraviolet emission properties at 380 nm, while no defect-related visible emission is detected. The good performance for photoluminescence emission makes the porous ZnO nanobelts promising candidates for photonic and electronic device applications. 相似文献
10.
Single-crystalline gallium nitride nanobelts have been synthesized through the reaction of gallium vapor with flowing ammonia using nickel as a catalyst. The as-synthesized products were characterized using X-ray powder diffraction (XRD), scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and selected-area electron diffraction (SAED). XRD and SAED results revealed that the products are pure, single-crystalline GaN with hexagonal structure. The widths and thickness of the nanobelts ranged from 80 to 200 nm, and 10 to 30 nm, respectively. The lengths were up to several tens of micrometers. The nanobelts had smooth surface with no amorphous sheath, and a sharp-tip end. The growth mechanism of nanobelts was discussed. 相似文献
11.
P. Yang M. Lü D. Xu D. Yuan C. Song G. Zhou 《Applied Physics A: Materials Science & Processing》2002,74(4):525-528
Direct synthesis of ZnS nanocrystallites doped with Ti3+ or Ti4+ by precipitation has led to novel photoluminescence properties. Detailed X-ray diffraction (XRD), fluorescence spectrophotometry,
UV–vis spectrophotometry and X-ray photoelectron spectroscopy (XPS) analysis reveal the crystal lattice structure, average
size, emission spectra, absorption spectra and composition. The average crystallite size doped with different mole ratios,
estimated from the Debye–Scherrer formula, is about 2.6±0.2 nm. The nanoparticles can be doped with Ti3+ and Ti4+ during the synthesis without the X-ray diffraction pattern being altered. The strong and stable visible-light emission has
been observed from ZnS nanocrystallites doped with Ti3+ (its maximum fluorescence intensity is about twice that of undoped ZnS nanoparticles). However, the fluorescence intensity
of the ZnS nanocrystallites doped with Ti4+ is almost the same as that of the undoped ZnS nanoparticles. The emission peak of the undoped sample is at 440–450 nm. The
emission spectrum of the doped sample consists of two emission peaks, one at 420–430 nm and the other at 510 nm.
Received: 27 April 2001 / Accepted: 16 August 2001 / Published online: 17 October 2001 相似文献
12.
P. Yang M. Lü D. Xü D. Yuan G. Zhou 《Applied Physics A: Materials Science & Processing》2001,73(4):455-458
Free-standing powders of doped ZnS nanoparticles have been synthesized by using a chemical co-precipitation of Zn2+, Mn2+, Cu2+ and Cd2+ with sulfur ions in aqueous solution. X-ray diffraction analysis shows that the diameter of the particles is ∼2–3 nm. The
unique luminescence properties, such as the strength (its intensity is about 12 times that of ZnS nanoparticles) and stability
of the visible-light emission, were observed from ZnS nanoparticles co-doped with Cu2+ and Mn2+. The nanoparticles could be doped with copper and manganese during the synthesis without altering the X-ray diffraction pattern.
However, doping shifts the luminescence to 520–540 nm in the case of co-doping with Cu2+ and Mn2+. Doping also results in a blue shift on the excitation wavelength. In Cd2+-doped ZnS nanometer-scale particles, the fluorescence spectra show a red shift in the emission wavelength (ranging from 450 nm
to 620 nm). Also a relatively broad emission (ranging from blue to yellow) has been observed. The results strongly suggest
that doped ZnS nanocrystals, especially two kinds of transition metal-activated ZnS nanoparticles, form a new class of luminescent
materials.
Received: 16 October 2000 / Accepted: 17 October 2000 / Published online: 23 May 2001 相似文献
13.
P.D. Townsend R. Brooks D.E. Hole Z. Wu A. Turkler N. Can A. Suarez-Garcia J. Gonzalo 《Applied physics. B, Lasers and optics》2001,73(4):345-353
The presence of copper nanoparticles in alumina and silica modifies their luminescence, and the changes in spectra are influenced
by variations in the nanoparticle size distributions. Luminescence signals are sensitive to the total defect population. Thus
the luminescence not only reflects changes caused by thermal annealing, which can modify both intrinsic defects and the copper
nanoparticles, but also responds to the method of preparation of thin film layers. Copper nanoparticle influence on luminescence
is reported both for ion-implanted bulk silica and for copper in pulsed laser deposition within alumina. Luminescence thus
potentially offers a non-destructive monitor of the layer quality, reproducibility and growth conditions, as well as the state
and size of the copper nanoparticles.
Received: 29 June 2001 / Published online: 10 October 2001 相似文献
14.
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
15.
Fabrication and characterization of In2O3 nanowires 总被引:1,自引:0,他引:1
L. Dai X.L. Chen J.K. Jian M. He T. Zhou B.Q. Hu 《Applied Physics A: Materials Science & Processing》2002,75(6):687-689
In2O3 nanowires were successfully fabricated through a simple gas-reaction route in argon atmosphere. These nanowires have diameters
ranging from 20 nm to 50 nm and lengths up to tens of micrometers. High-resolution transmission electron microscopy observations
and the electron-diffraction (ED) pattern reveal that the In2O3 nanowires are formed by the stacking of (2) planes along the [1] direction, which is parallel to the wire axis. A strong and wide ultraviolet (UV) emission band centered at around 392 nm
is observed for the first time in the room-temperature photoluminescence measurement in addition to the usual blue emission
(468 nm). Moreover, five discrete fine peaks (372 nm, 383 nm, 406 nm, 392 nm and 413 nm) are further identified in this broad
UV band.
Received: 10 April 2002 / Accepted: 12 April 2002 / Published online: 19 July 2002 相似文献
16.
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
17.
K. Shimotani K. Anazawa H. Watanabe M. Shimizu 《Applied Physics A: Materials Science & Processing》2001,73(4):451-454
We have synthesized multi-walled carbon nanotubes (MWNTs) using a DC arc discharge method under organic molecular atmospheres.
This method allows us to synthesize about five times more MWNTs than are synthesized using the usual arc discharge method,
using discharge conditions of 100 A and 20 V. We have examined the synthetic yield of MWNTs at various pressures under different
organic atmospheres. The yield of MWNTs increases with the number of carbon atoms in the organic molecule.
Received: 21 September 2000 / Accepted: 18 December 2000 / Published online: 26 April 2001 相似文献
18.
K. Elihn F. Otten M. Boman P. Heszler F.E. Kruis H. Fissan J.-O. Carlsson 《Applied Physics A: Materials Science & Processing》2001,72(1):29-34
Iron-containing nanoparticles were made by laser-assisted (ArF excimer laser, λ=193 nm) photolytic dissociation of ferrocene
(Fe(C5H5)2 or FeCp2) in argon and an oxygen/argon gas mixture. The particle-size distributions were obtained on-line by using differential mobility
analysers (DMAs) and were found to be log-normal with a geometric standard deviation of 1.85. In argon, particle sizes between
3 and 100 nm were generated. The volumes of these particles were found to increase linearly with the increased repetition
rate, fluence and beam size of the laser. These observations are explained on the basis of the residence-time approach model.
Received: 23 November 1999 / Accepted: 19 September 2000 / Published online: 22 November 2000 相似文献
19.
Morphologies of GaN one-dimensional materials 总被引:8,自引:0,他引:8
J.Y. Li Z.Y. Qiao X.L. Chen Y.G. Cao Y.C. Lan C.Y. Wang 《Applied Physics A: Materials Science & Processing》2000,71(5):587-588
GaN one-dimensional materials with different morphologies were formed on LaAlO3 crystal, silicon crystal and quartz glass substrates through a simple sublimation method. They were characterized by powder
X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray (EDX) spectroscopy.
FE-SEM images showed that the morphologies of the one-dimensional materials included straight nanorods, curved nanowires,
nanoribbons, zigzag nanorods and beaded or capture-tree nanorods. XRD and EDX studies indicated that all the one-dimensional
materials were wurtzite GaN.
Received: 14 July 2000 / Accepted: 17 July 2000 / Published online: 20 September 2000 相似文献
20.
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