共查询到20条相似文献,搜索用时 31 毫秒
1.
A.V. Karabutov V.D. Frolov E.N. Loubnin A.V. Simakin G.A. Shafeev 《Applied Physics A: Materials Science & Processing》2003,76(3):413-416
Low-threshold field electron emission (FEE) is reported for periodic arrays of micro-tips produced by laser ablation of Si
wafers. The best samples show emission at threshold fields as low as 4–5 V/μm for n-type Si substrates and of 1–2 V/μm for
p-doped Si substrates, as measured with a flat-screen technique. Auger electron spectroscopy and X-ray electron spectroscopy
reveal island-like deviation of the SiO2 stoichiometry on the tip surfaces, with lateral dimensions of less than 100 nm. Microscopic studies using a special field-emission
STM show that the emission originates from well-conducting regions of sub-micron size. The experimental data suggest FEE from
the tip arrays by a geometric field enhancement of both the individual micro-tip and the narrow conducting channels in the
tip body.
Received: 3 May 2002 / Accepted: 1 July 2002 / Published online: 28 October 2002
RID="*"
ID="*"Corresponding author. Fax: +7-095/135-82-34, E-mail: shafeev@kapella.gpi.ru 相似文献
2.
G.S. Wang X.J. Meng Z.Q. Lai J. Yu J.L. Sun S.L. Guo J.H. Chu 《Applied Physics A: Materials Science & Processing》2003,76(1):83-86
Ferroelectric Bi3.25La0.75Ti3O12 (BLT) thin films have been grown on Pt/Ti/SiO2/Si substrates by chemical solution methods. X-ray diffraction analysis shows that BLT thin films are polycrystalline with
(171)-preferential orientation. Atomic force microscopy investigation shows that they have large grains about 120 nm in size.
A Pt/BLT/Pt capacitor has been fabricated and showed excellent ferroelectricity, with a remnant polarization and coercive
field of 24 μC/cm2 and 116 kV/cm, respectively. The capacitor shows no polarization fatigue up to 109 switching cycles. The optical constants (n,k) of the BLT thin films in the wavelength range 0.35–1.7 μm were obtained by
spectroscopic ellipsometry measurements, and the band-gap energy was found to be about 3.25 eV.
Received: 16 October 2001 / Accepted: 6 January 2002 / Published online: 3 June 2002
RID="*"
ID="*"Corresponding author. Fax: +86-21/65830-734, E-mail: gswang@mail.sitp.ac.cn 相似文献
3.
Oxygen plasma and high pressure H2O vapor heat treatment were applied to fabrication of n-channel polycrystalline silicon thin film transistors (poly-Si TFTs).
13.56 MHz-oxygen-plasma treatment at 250 °C, 100 W for 5 min effectively reduced defect states of 25-nm-thick silicon films
crystallized by 30 ns-pulsed XeCl excimer laser irradiation. 1.3×106-Pa-H2O vapor heat treatment at 260 °C for 3 h was carried out in order to improve electrical properties of SiOx gate insulators and SiOx/Si interfaces. A carrier mobility of 470 cm2/V s and a low threshold voltage of 1.8 V were achieved for TFTs fabricated with crystallization at 285 mJ/cm2.
Received: 18 November 2002 / Accepted: 25 November 2002 / Published online: 11 April 2003
RID="*"
ID="*"Corresponding author. Fax: +81-42/388-7109, E-mail: tsamesim@cc.tuat.ac.jp 相似文献
4.
R. Steiner H.-G. Boyen M. Krieger A. Plettl P. Widmayer P. Ziemann F. Banhart R. Kilper P. Oelhafen 《Applied Physics A: Materials Science & Processing》2003,76(1):5-13
[Fe/B]n ≥2 multilayers were prepared by thermal evaporation, ion-beam sputtering and laser ablation. By applying in situ electron spectroscopies
(UPS, XPS) and monitoring the electrical resistance during layer growth, evidence could be provided for the occurrence of
interface reactions within the range of studied deposition temperatures (77 K ≤T ≤300 K). These reactions result in amorphous
FexB100-x phases, which are spatially restricted to a width of less than 3 nm at the original interface. The amorphicity of the reacted
interlayers was unequivocally proven by additional high-resolution electron microscopy (HRTEM) and their characteristically
changed magnetic properties. Due to the well-defined width of the interface reaction, homogeneous amorphous FexB100-x films can be obtained by reducing the individual Fe and B layer thicknesses to below the above reaction depth, while for
larger thicknesses layer sequences of the crystalline/amorphous/crystalline type will result.
Received: 30 January 2002 / Accepted: 31 January 2002 / Published online: 10 September 2002
RID="*"
ID="*"Corresponding author. Fax: +49-731/502-2963, E-mail: hans-gerd.boyen@physik.uni-ulm.de 相似文献
5.
Manganese oxide (hausmannite) nanowires were prepared by annealing precursor powders at a temperature of 800 °C for 3 h, which
were produced in a novel inverse microemulsion (IμE) system. The microstructures of the as-prepared Mn3O4 nanowires were investigated by means of X-ray diffraction, transmission electron microscopy, and Raman spectra. It has been
found that the Mn3O4 nanowires were relatively straight and their surfaces were smooth with a typical diameter of 75–150 nm. The formation mechanism
of the Mn3O4 nanowires is discussed.
Received: 30 May 2002 / Accepted: 7 October 2002 / Published online: 17 December 2002
RID="*"
ID="*"Corresponding author. Fax: +86-25/359-5535, E-mail: wangqun@nju.edu.cn 相似文献
6.
LiMnO2 nanowire arrays were prepared using a porous anodic aluminum oxide (AAO) template from a sol–gel solution containing Li(OAc)
and Mn(OAc)2. Electron-microscope results showed that a uniform length and diameter of LiMnO2 nanowires were obtained, and the length and diameter of the LiMnO2 nanowires are dependent on the pore diameter and the thickness of the applied AAO template. X-ray diffraction and electron
diffraction pattern investigations demonstrate that LiMnO2 nanowires are a layered structure of LiMnO2 crystal. X-ray photoelectron spectroscopy analysis indicates that a material closely resembling stoichiometric layered LiMnO2 has been obtained.
Received: 2 September 2001 / Accepted: 6 January 2002 / Published online: 10 September 2002
RID="*"
ID="*"Corresponding author. Fax: +86-931/891-2582, E-mail: lihl@lzu.edu.cn 相似文献
7.
D. Golberg P.S. Dorozhkin Y. Bando Z.-C. Dong C.C. Tang Y. Uemura N. Grobert M. Reyes-Reyes H. Terrones M. Terrones 《Applied Physics A: Materials Science & Processing》2003,76(4):499-507
Transport and field-emission properties of as-synthesized CNx and BNCx (x<0.1) multi-walled nanotubes were compared in detail. Individual ropes made of these nanotubes and macrofilms of those
were tested. Before measurements, the nanotubes were thoroughly characterized using high-resolution and energy-filtered electron
microscopy, electron diffraction and electron-energy-loss spectroscopy. Individual ropes composed of dozens of CNx nanotubes displayed well-defined metallic behavior and low resistivities of ∼10–100 kΩ or less at room temperature, whereas
those made of BNCx nanotubes exhibited semiconducting properties and high resistivities of ∼50–300 MΩ. Both types of ropes revealed good field-emission
properties with emitting currents per rope reaching ∼4 μA(CNx) and ∼2 μA (BNCx), albeit the latter ropes se- verely deteriorated during the field emission. Macrofilms made of randomly oriented CNx or BNCx nanotubes displayed low and similar turn-on fields of ∼2–3 V/μm. 3 mA/cm2 (BNCx) and 5.5 mA/cm2 (CNx) current densities were reached at 5.5 V/μm macroscopic fields. At a current density of 0.2–0.4 mA/cm2 both types of compound nanotubes exhibited equally good emission stability over tens of minutes; by contrast, on increasing
the current density to 0.2–0.4 A/cm2, only CNx films continued to emit steadily, while the field emission from BNCx nanotube films was prone to fast degradation within several tens of seconds, likely due to arcing and/or resistive heating.
Received: 29 October 2002 / Accepted: 1 November 2002 / Published online: 10 March 2003
RID="*"
ID="*"Corresponding author. Fax: +81-298/51-6280, E-mail: golberg.dmitri@nims.go.jp 相似文献
8.
β-Ga2O3 nanowires have been synthesized using Ga metal and H2O vapor at 800 °C in the presence of Ni catalyst on the substrate. Remarkable reduction of the diameter and increase of the
length of the Ga2O3 nanowires are achieved by separation of Ga metal and H2O vapor before they reach the substrate. Transmission electron microscopy analyses indicate that the β-Ga2O3 nanowires possess a single-crystalline structure. Photoluminescence measurements show two broad emission bands centered at
290 nm and 390 nm at room temperature.
Received: 27 June 2002 / Accepted: 7 October 2002 / Published online: 17 December 2002
RID="*"
ID="*"Corresponding author. Fax: +886-6/234-4496, E-mail: wujj@mail.ncku.edu.tw 相似文献
9.
V.C. Selvaraju S. Asokan V. Srinivasan 《Applied Physics A: Materials Science & Processing》2003,77(1):149-153
The I–V characteristics of bulk As40Te60-xSex and As35Te65-xSex glasses have been studied with a current sweep of 0–18 mA-0, over a wide range of compositions (4≤x≤22). All the glasses
studied showed a threshold electrical switching behaviour. The number of switching cycles withstood by the samples has been
found to depend on the ON-state current. It is seen that the switching voltages increase with increase in selenium content.
Further, the switching voltages are found to be almost independent of the thickness of the sample (d), in the range 0.18–0.3 mm.
Also, the switching voltages and the number of switching cycles withstood by the samples are found to decrease with temperature.
Received: 6 November 2002 / Accepted: 8 November 2002 / Published online: 29 January 2003
RID="*"
ID="*"Corresponding author. Fax: +91-80/360-0135, E-mail: sasokan@isu.iisc.ernet.in 相似文献
10.
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
11.
Y. Liu D. Li R.Y. Zhu G.J. You S.X. Qian Y. Yang J.L. Shi 《Applied physics. B, Lasers and optics》2003,76(4):435-439
Au-core CdS-shell composite nanoparticles were synthesized by a direct self-assembly process and integrated into BaTiO3 thin films. Characterization by transmission electron microscopy showed that the average diameter of these composite nanoparticles
was about 8 nm. Using the femtosecond time-resolved optical Kerr effect method, we investigated the third-order nonlinear
optical response of the Au@CdS nanoparticles embedded in the BaTiO3 thin films at a wavelength of 800 nm. An ultrafast nonlinear response and a large effective third-order nonlinear susceptibility
of χ(3)=7.7×10-11 esu were observed. We attributed the enhancement of the third-order optical nonlinearity to a localized electric field effect
originating from the core-shell structure under off-surface-plasmon resonance conditions.
Received: 13 May 2002 / Revised version: 23 October 2002 / Published online: 3 April 2003
RID="*"
ID="*"Corresponding author. Fax: +86-21/6510-4949, E-mail: sxqian@fudan.ac.cn 相似文献
12.
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
13.
T. Ohtsubo T. Azuma M. Takaura T. Higashiguchi S. Kubodera W. Sasaki 《Applied Physics A: Materials Science & Processing》2003,76(2):139-141
We have demonstrated the non-thermal removal of oxygen atoms from an oxidized silicon surface (SiO2) on a silicon wafer by the use of a low-power (0.3 mW cm-2) incoherent vacuum ultraviolet (VUV) light source at 126 nm. X-ray photoelectron spectroscopy (XPS) has shown that a maximum
Si concentration of 80% appears at the surface after a 20-h irradiation with 9.8 eV photons, as a result of oxygen removal
from the SiO2 matrix. The surface morphology, however, indicates no damage or melting on the surface even after the irradiation.
Received: 15 April 2002 / Accepted: 17 April 2002 / Published online: 10 September 2002
RID="*"
ID="*"Permanent address: Nano-Tech Photon Inc., Shimotomita 4132-1, Shintomi, Miyazaki, 889-1404, Japan
RID="**"
ID="**"Corresponding author. Fax: +81-985/583-899, E-mail: kubodera@opt.miyazaki-u.jp 相似文献
14.
T. Okazaki T. Shimada K. Suenaga Y. Ohno T. Mizutani J. Lee Y. Kuk H. Shinohara 《Applied Physics A: Materials Science & Processing》2003,76(4):475-478
Electronic properties of Gd@C82 metallofullerene peapods, (Gd@C82)n@SWNTs, were investigated by electron energy-loss spectroscopy (EELS), scanning tunneling microscopy and spectroscopy (STM/STS),
and field-effect transistor (FET) transport measurements. The results indicate that the electronic structure of Gd@C82 metallofullerene peapods is completely different from that of intact single-walled nanotubes (SWNTs). For example, Gd@C82-peapod-FETs show ambipolar behavior which is not observed in the empty SWNT-FETs under our experimental conditions. Furthermore,
in semiconducting nanotubes the band gap can be varied from ∼0.5 to ∼0.1 eV using inserted Gd@C82 endohedral metallofullerenes with a spatial periodicity of 1.1 to 8.0 nm, depending on the density of the fullerenes. The
present findings suggest that metallofullerene peapods may point the way toward novel electronic devices.
Received: 6 September 2002 / Accepted: 25 October 2002 / Published online: 10 March 2003
RID="*"
ID="*"Corresponding author. Fax: +81-52/789-1169, E-mail: noris@cc.nagoya-u.ac.jp 相似文献
15.
J. Ihlemann S. Müller S. Puschmann D. Schäfer M. Wei J. Li P.R. Herman 《Applied Physics A: Materials Science & Processing》2003,76(5):751-753
Submicron surface-relief gratings were fabricated on fused silica by F2-laser ablation with nanosecond duration pulses from a high-resolution 157-nm optical processing system. A 157 nm wavelength
projection mask was prepared by ArF-laser ablation to form a 20-μm period grating of equal lines and spaces. A 25-fold demagnification
of the mask by a Schwarzschild objective generated gratings of an 830-nm period and a 250 nm modulation depth, as characterized
by SEM, AFM and HeNe-laser beam diffraction.
Received: 24 April 2002 / Accepted: 25 April 2002 / Published online: 4 December 2002
RID="*"
ID="*"Corresponding author. Fax: +49-551/503 599, E-mail: jihle@llg.gwdg.de 相似文献
16.
F.C. Fonseca G.F. Goya R.F. Jardim N.L.V. Carreño E. Longo E.R. Leite R. Muccillo 《Applied Physics A: Materials Science & Processing》2003,76(4):621-623
Ni nanoparticles embedded in an amorphous SiO2 matrix were produced by a modified sol–gel method. This method resulted in nanocomposites with a controlled size distribution
and good dispersion of the metallic particles. The particle-size distributions were found to have an average radius of ∼3 nm,
as inferred from transmission electron microscopy, X-ray-diffraction analysis, and magnetic measurements. Magnetic characterizations
revealed that samples exhibit superparamagnetic behavior above the blocking temperature TB, 20 K≤TB≤40 K, and absence of a shift along the field axis on hysteresis loops measured at T≤TB, indicating that the metallic nanoparticles are also free from an oxide layer.
Received: 7 October 2002 / Accepted: 9 October 2002 / Published online: 8 January 2003
RID="*"
ID="*"Corresponding author. Fax: +55-11/3091-6984, E-mail: rjardim@if.usp.br 相似文献
17.
Silicon nanowires grown from Au-coated Si substrate 总被引:1,自引:0,他引:1
Xing Y.J. Yu D.P. Xi Z.H. Xue Z.Q. 《Applied Physics A: Materials Science & Processing》2003,76(4):551-553
Amorphous Si nanowires were grown on an Au-coated Si substrate by heat treatment at 1000 °C under an H2 atmosphere. The nanowires have a length of several tens of a micron and a diameter of 10–20 nm. The growth mechanism of the
nanowires was investigated and explained with a solid–liquid–solid model.
Received: 11 July 2002 / Accepted: 7 July 2002 / Published online: 4 December 2002
RID="*"
ID="*"Corresponding author. Fax: +86/10-62751615, E-mail: yudp@pku.edu.cn 相似文献
18.
Z.J. Li H.J. Li X.L. Chen A.L. Meng K.Z. Li Y.P. Xu L. Dai 《Applied Physics A: Materials Science & Processing》2003,76(4):637-640
Large quantities of high-purity crystalline β-SiC nanowires have been synthesized at relatively low temperature via a new
simple method, the chemical-vapor-reaction approach, in a home-made graphite reaction cell. A mixture of milled Si and SiC
powders and C3H6 were employed as the starting materials. The results show that the nanowires with diameters of about 10–35 nm are single
crystalline β-SiCwithout any wrapping of amorphous material, and the nanowire axes lie along the 〈111〉 direction. Some unique
properties are found in the Raman scattering from the β-SiC nanowires, which are different from previous observations of β-SiC
materials. A possible growth mechanism for the β-SiC nanowires is proposed.
Received: 27 August 2002 / Accepted: 28 August 2002 / Published online: 4 December 2002
RID="*"
ID="*"Corresponding author. Fax: +86-29/8491-000, E-mail: zjli-sohu@sohu.com 相似文献
19.
P.E. Dyer S.M. Maswadi C.D. Walton 《Applied Physics A: Materials Science & Processing》2003,76(5):817-822
We report an investigation of the ablation of NaCl crystals at the 157-nm wavelength of the F2 laser where there is very strong excitonic absorption. Probe-beam deflection and etch-rate measurements show that the interaction
is characterised by a low ablation threshold (∼80 mJ cm-2) and a capability for controllable material removal at the nanometer level. Scanning electron microscopy of the exposed surfaces
show this to be microscopically smooth but with fine cracks present. It is demonstrated that micron-scale features can be
formed in NaCl using 157-nm laser ablation, a result attributed to the strongly localised optical and thermal nature of the
interaction. The results are discussed within the framework of a thermal vaporisation model.
Received: 29 May 2002 / Accepted: 17 July 2002 / Published online: 4 November 2002
RID="*"
ID="*"Corresponding author. Fax: +44-1482/465606, E-mail: p.e.dyer@hull.ac.uk 相似文献
20.
J.C. Bermudez Gutierrez M.J. Damzen V.J. Pinto-Robledo A.V. Kir’yanov J.J. Soto-Bernal 《Applied physics. B, Lasers and optics》2003,76(1):13-16
The analysis of compact CW diode-side-pumped grazing-incidence-geometry Nd:YVO4 laser designs is presented. An output power of 5 W (λ=1064 nm) was produced at 17 W of diode pump (conversion efficiency
of 30%) in single transverse TEM00 mode operation at high laser beam quality (Mx
2≈1.05 and My
2≈1.01). The resonator geometry was analyzed by applying generalized 4×4 matrix modeling of the spatial mode size, including
the impact on the laser operation of cavity astigmatism and a thermal lens in the laser slab. The simplicity and compactness
of the laser cavities allow their use for technological applications.
Received: 31 July 2002 / Published online: 22 January 2003
RID="*"
ID="*"Corresponding author. Fax: +44-20/7594-7744, E-mail: m.damzen@ic.ac.uk 相似文献