共查询到20条相似文献,搜索用时 78 毫秒
1.
T.J. Kulp S.E. Bisson R.P. Bambha T.A. Reichardt U.-B. Goers K.W. Aniolek D.A.V. Kliner B.A. Richman K.M. Armstrong R. Sommers R. Schmitt P.E. Powers O. Levi T. Pinguet M. Fejer J.P. Koplow L. Goldberg T.G. McRae 《Applied physics. B, Lasers and optics》2002,75(2-3):317-327
Quasi-phase-matched (QPM) materials allow the generation of spectroscopically useful infrared radiation in an efficient and
broadly tunable format. Here, we describe several applications of QPM-based light sources to remote and local chemical sensing.
The remote systems are gas imagers that employ a fiber-pumped continuous-wave optical parametric oscillator or a microlaser-pumped,
diode-seeded optical parametric amplifier as the illumination source. Technology described for local sensing includes a cavity
ring down spectrometer that employs a novel optical parametric generator–amplifier to achieve ≥350 cm-1 of contiguous tuning and a long-wave infrared light source based on QPM GaAs. In each case the use of QPM materials in conjunction
with effective pump sources instills simplicity and ruggedness into the sensing systems.
Received: 15 April 2002 / Revised version: 6 June 2002 / Published online: 12 September 2002
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ID="*"Corresponding author. Fax: +1-925/294-2595, E-mail: tjkulp@sandia.gov
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ID="**"Present address: Corning Inc., Corning, NY 14831, USA
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ID="*"Present address: Corning Inc., Corning, NY 14831, USA
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ID="**"Present address: Blue Leaf Networks, Sunnyvale, CA 94086, USA
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ID="***"Present address: Sandia National Laboratories, Albuquerque, NM 87185, USA 相似文献
2.
G. Stobrawa M. Hacker R. Netz M. Bischoff R. Sauerbrey 《Applied physics. B, Lasers and optics》2003,76(3):333-336
We present a novel method for measuring the linear and nonlinear dispersion properties of conventional and micro-structured
fibers. It is based on the automated compensation of phase modulations using a high-resolution pulse-shaping device. No tunable
laser source is required.
Received: 20 December 2002 / Published online: 19 March 2003
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ID="*"Corresponding author. Fax: +49-3641/947202, E-mail: stobrawa@ioq.uni-jena.de
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ID="**"Present address: Carl Zeiss Meditec AG, G?schwitzer Strasse 51–52, 07745 Jena, Germany 相似文献
3.
The temperature and excitation wavelength dependencies of 3-pentanone absorption and fluorescence were studied in support
of planar laser-induced fluorescence (PLIF) imaging of temperature and mixture fraction in flows of practical interest. The
temperature dependencies (300–875 K) of absorption and fluorescence were measured for gaseous 3-pentanoneat atmospheric pressure
in a nitrogen bath gas using 248, 266, and 308 nm excitation. The results indicate that the fluorescence signal per unit mole
fraction using 248 nm excitation is highly temperature-sensitive below 600 K, while the signal from 308 nm excitation is not
temperature sensitive below 500 K. For quantitative measurements over a broad range of temperatures, one must choose excitation
schemes carefully to balance the trade-off between measurement sensitivity and the amount of signal at the expected conditions.
As an example of such a choice and to show the capabilities of ketone PLIF techniques, we include temperature and mixture
fraction images of a 300–650 K heated air jet using near-simultaneous 308 and 266 nm excitation.
Received: 29 May 2002 / Revised version: 5 November 2002 / Published online: 26 February 2003
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ID="*"Corresponding author. Fax: +1-650/723-1748, E-mail: jkoch@stanford.edu
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ID="**"E-mail: hanson@me.stanford.edu 相似文献
4.
Bulk heating of transparent materials using a high-repetition-rate femtosecond laser 总被引:7,自引:0,他引:7
C.B. Schaffer J.F. García E. Mazur 《Applied Physics A: Materials Science & Processing》2003,76(3):351-354
Femtosecond laser pulses can locally induce structural and chemical changes in the bulk of transparent materials, opening
the door to the three-dimensional fabrication of optical devices. We review the laser and focusing parameters that have been
applied to induce these changes and discuss the different physical mechanisms that play a role in forming them. We then describe
a new technique for inducing refractive-index changes in bulk material using a high-repetition-rate femtosecond oscillator.
The changes are caused by a localized melting of the material, which results from an accumulation of thermal energy due to
nonlinear absorption of the high-repetition-rate train of laser pulses.
Received: 21 November 2001 / Accepted: 9 July 2002 / Published online: 25 October 2002
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ID="*"Corresponding author. Fax: +1-858/534-7697, E-mail: cschaffer@ucsd.edu
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ID="**"Current address: University of California, San Diego, Department of Physics, La Jolla, CA 92 093, USA 相似文献
5.
R.A. Pérez F. Dyment G. García Bermúdez D. Abriola M. Behar 《Applied Physics A: Materials Science & Processing》2003,76(2):247-250
The diffusion of Ta in the hcp (α) phase of high-purity Ti (99.99%) was studied at different temperatures from 911 K up to
1123 K. The Rutherford Backscattering Spectrometry (RBS) and Heavy Ion RBS (HIRBS) techniques were used to obtain the penetration
profiles. The evolution of the diffusion coefficient, D, as a function of temperature follows prediction of the Arrhenius
law. The activation energy of the diffusion process is (318±7)kJ/mol, similar to that corresponding to self-diffusion in α-Ti.
On the other hand, the measured values of D are systematically lower than those corresponding to self-diffusion by a factor
of approximately 5. This reduction could be explained by taking into account the mass difference between Ta and Ti. An increase
of the diffusion coefficient was measured when the diffusion proceeds on a less pure Ti (99.9%) matrix. This increment is
higher at lower temperatures.
Received: 12 November 2001 / Accepted: 12 March 2002 / Published online: 5 July 2002
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ID="*"
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ID="*"
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ID="**"Corresponding author. Fax: +54-11/6772-7362, E-mail: dyment@cnea.gov.ar
RID="*"
ID="*"Members of the Carrera del Investigador Científico del Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET),
Argentina 相似文献
6.
R.A. Ganeev R.I. Tugushev A.A. Ishchenko N.A. Derevyanko A.I. Ryasnyansky T. Usmanov 《Applied physics. B, Lasers and optics》2003,76(6):683-686
We investigated nonlinear refraction, nonlinear absorption, and saturable absorption of polymethine dyes by the Z-scan technique
(λ=1064 nm). The analysis of simultaneous appearance of several nonlinear optical processes in dye solutions excited by picosecond
pulses was carried out. The saturable absorption was analyzed taking into account various models. Nonlinear refractive indices,
nonlinear absorption coefficients, and saturation intensities of various polymethine dyes were measured.
Received: 27 December 2002 / Revised version: 6 March 2003 / Published online: 5 May 2003
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ID="*"Corresponding author. Fax: +81-471/363-366, E-mail: r_ganeev@issp.u-tokyo.ac.jp
RID="**"
ID="**"Present address: The Institute for Solid State Physics, The Tokyo University, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581,
Japan 相似文献
7.
We examine in detail the theory of the intrinsic non-linearities in the dynamics of trapped ions due to the Coulomb interaction.
In particular, the possibility of mode–mode coupling, which can be a source of decoherence in trapped ion quantum computation,
or can be exploited for parametric down-conversion of phonons, is discussed and conditions under which such coupling is possible
are derived.
Received: 8 November 2002 / Published online: 26 March 2003
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ID="*"Permanent address: MIP, Université Pierre et Marie Curie and Département de Physique, école Normale Supérieure, 75005
Paris, France
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ID="**"Corresponding author. Fax: +1-505/667-1931, E-mail: dfvj@lanl.gov 相似文献
8.
E. Gehrig O. Hess C. Seibert D. Woll R. Wallenstein 《Applied physics. B, Lasers and optics》2003,76(3):285-288
We theoretically describe and experimentally investigate the spatio-spectral wave mixing of induced and spontaneous emission
in large-area InGaAs-semiconductor laser amplifiers. The dynamic light-matter-coupling is described by a spatially resolved
theory based on Maxwell–Bloch–Langevin equations, taking into account many-body-carrier interactions, energy transfer between
the carrier and phonon systems and, in particular, the spatio-temporal interplay of stimulated and amplified spontaneous emission
and the noise caused by spontaneous emission. Our numerical model reveals the fundamental physical processes which are responsible
for the spectral power distribution of the amplified laser light and predicts the emission properties of high-power semiconductor
laser amplifiers, such as emission spectra and input power–output power characteristics.
Received:30October2002/Revisedversion:21November2002 / Published online: 12 February 2003
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ID="*"Corresponding author. Fax: +49-711/6862-349, E-mail: Edeltraud.Gehrig@dlr.de
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ID="**"Also at: Institute of Physics, Tampere University of Technology, P.O. Box 692, FIN-33101, Tampere, Finland
RID="***"
ID="***"Present address: Heidelberger Druckmaschinen AG, Speyerer Strasse 6, 69115 Heidelberg, Germany
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ID="****"Present address: Lightbit Corporation, 411 Clyde Avenue, Mountain View, CA 94043, USA 相似文献
9.
Wilpers G. Degenhardt C. Binnewies T. Chernyshov A. Riehle F. Helmcke J. Sterr U. 《Applied physics. B, Lasers and optics》2003,76(2):149-156
We have investigated the two major effects that limit the accuracy of an optical frequency standard based on laser-cooled
neutral calcium atoms, i.e. the residual Doppler shift and atomic collisions. A new correction method was applied to reduce
the contribution of the residual Doppler effect to the total fractional uncertainty to 1×10-14. Measurements of the shift of the clock transition frequency due to cold collisions allowed us to reduce their contribution
to 4×10-15. With these improvements we have reduced the total fractional frequency uncertainty of the standard by nearly an order of
magnitude to 2×10-14.
Received: 9 August 2002 / Revised version: 16 November 2002 / Published online: 26 February 2003
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ID="*"Permanent address: Russian Academy of Sciences, P.N. Lebedev Physical Institute, Samara Branch, Novo-Sadovaya st. 221,
Samara 443011, Russia
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ID="**"Corresponding author. Fax: +49-531/592-4305, E-mail: uwe.sterr@ptb.de 相似文献
10.
Silver colloids in aqueous solution were studied by different scanning microscopy techniques and UV/VIS spectroscopy. The
silver colloids were produced either by chemical reduction or by nanosecond laser ablation from a solid silver foil in water.
Variation of laser power and ablation time leads to solutions of metal clusters of different sizes in water. We characterized
the electronic absorption of the clusters by UV/VIS spectroscopy. STM (scanning tunneling microscope) imaging of the metal
colloids shows atomic resolution of rod- or tenon-like silver clusters up to 10-nm length formed by laser ablation. Our scanning
electron microscope measurements, however, show that much larger silver colloids up to 5-μm length are also formed, which
are not visible in the STM due to their roughness. We correlate them with the long-wavelength tail of the multimodal UV/VIS
spectrum. The silver colloids obtained by chemical reduction are generally larger and their electronic spectra are red-shifted
compared to the laser-ablated clusters. Irradiation of the colloid solution with nanosecond laser pulses of appropriate fluence
at 532 nm and 355 nm initially reduced the colloid size. Longer irradiation at 355 nm, however, leads to the formation of
larger colloids again. There seems to be a critical lower particle size, where silver clusters in aqueous solution become
unstable and start to coagulate.
Received: 24 June 2002 / Revised version: 25 July 2002 / Published online: 25 October 2002
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ID="*"This work is part of the thesis of H. M?ltgen
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ID="**"Corresponding author. Fax: +49-211/811-5195, E-mail: kleinermanns@uni-duesseldorf.de 相似文献
11.
K.P. Unnikrishnan J. Thomas V.P.N. Nampoori C.P.G. Vallabhan 《Applied physics. B, Lasers and optics》2002,75(8):871-874
The wavelength dependence of the nonlinear absorption of a bis-phthalocyanine, Nd(Pc)2, dissolved in dimethyl formamide was studied in the rising part of the Q-band using the open aperture Z-scan technique, to
determine the wavelength region over which the nonlinear absorption changes from reverse saturable absorption to saturable
absorption. It was found that the sample could be used as a reverse saturable absorber, and hence as an optical limiter, up
to a wavelength of about 604 nm. The imaginary part of the third order susceptibility was also calculated for these wavelengths.
Resonant enhancement of the imaginary part of the third order susceptibility was clearly observed.
Received: 26 April 2002 / Revised version: 30 June 2002 / Published online: 20 December 2002
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ID="*"Corresponding author. Fax: +91-484/576-714, E-mail: kpu@cusat.ac.in
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ID="**"Present address: Optical Sciences Center, University of Arizona, Tucson, USA 相似文献
12.
A versatile CO laser-based photoacoustic spectrometer is presented equipped with three photoacoustic cells placed inside the
laser cavity. The newly designed CO laser can operate both in the Δv=1 and the Δv=2 modes (5.1–8.0 μm and 2.8–4.1 μm) on 400
laser lines. Improved laser operation originating from a better cooling of the gas discharge was evidenced by a shift of the
laser output power to lower J-values. Due to the wide emission range of the source, many molecules of biological and atmospheric
interest, including methane and ethane, can be detected with sensitivities typically at the (sub)ppb level. Measurement of
the respiration of a cockroach showed that the spectrometer is not only sensitive, but also has a good time response (8 s
at a flow rate of 10 l/h).
Received: 3 April 2002 / Revised version: 14 June 2002 / Published online: 21 August 2002
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ID="*"Current address: Soegijapranata Catholic University, Department of Food Technology, Jalan Pawiyatan Luhur IV/1 Bendan
Duwur, P.O. Box 8033/SM, Semarang 50234, Indonesia
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ID="**"Current address: Sanata Dharma University, FMIPA, Kampus III, Paingan, Maguwoharjo, Depok, Sleman, Tromol Pos 29, Yogyakarta
55002, Indonesia
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ID="***"Corresponding author. Fax: +31-24/365-3311, E-mail: fransh@ sci.kun.nl 相似文献
13.
A high-sensitivity in situ optical diagnostic technique for laser cleaning of transparent substrates
N. Chaoui J. Solis C.N. Afonso T. Fourrier T. Muehlberger G. Schrems M. Mosbacher D. Bäuerle M. Bertsch P. Leiderer 《Applied Physics A: Materials Science & Processing》2003,76(5):767-771
A differential optical transmission technique has been used to monitor in situ the efficiency of laser cleaning for the removal
of sub-micrometer-sized particles on substrates transparent at the monitoring wavelength. This technique has been applied
to the removal of sub-micrometer polystyrene particles on polyimide substrates using laser pulses of 30 ps duration at 292 nm
while probing the material transmission at 633 nm. The sensitivity achieved -1/104 for the transmission changes induced upon single-pulse laser exposure – allows us to monitor the removal of just a few sub-micron-sized
particles from the probed region inside the irradiated area.
Received: 2 October 2002 / Accepted: 7 October 2002 / Published online: 29 January 2003
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ID="*"Corresponding author. Fax: +33-3/87844082, E-mail: nchaoui@iut.univ-metz.fr
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ID="**"Present address: Laboratoire de Chimie et Applications, Institut Universitaire de Technologie de Metz, Département
Chimie, Rue Victor Demange, 57500 Saint-Avold, France 相似文献
14.
J. Luque R.J.H. Klein-Douwel J.B. Jeffries G.P. Smith D.R. Crosley 《Applied physics. B, Lasers and optics》2003,76(6):715-715
/ Published online: 11 June 2003
RID="*"
ID="*"Present address: Lam Research Corporation, Fremont, CA 94538, USA
RID="**"
ID="**"Present address: Mechanical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
RID="***"
ID="***"Present address: Mechanical Engineering Dept., Stanford University, Stanford CA 94305, USA
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ID="****"Corresponding author. Fax: +1-650/859-6196, E-mail: smith@mplvax.sri.com 相似文献
15.
G. Appel H. Ade A.G. Guerek S. Stadler R.P. Mikalo D. Schmeisser 《Applied Physics A: Materials Science & Processing》2003,76(2):177-182
Layers of dihydroxy silicon phthalocyanine tetrasulfonic acid and oligo-μ-oxo silicon phthalocyanine tetrasulfonic acid were
prepared by solution-casting methods. The purity of the material was checked by X-ray photoemission spectroscopy. The orientation
of the molecules in respect to the substrate plane was investigated by angle-dependent near-edge X-ray absorption fine-structure
spectroscopy. The morphology was characterized by atomic force microscopy. Most samples exhibited a significant orientation
that was accompanied by crystalline structures; others had no orientation at all with a dominant amorphous morphology. This
behavior indicates that several preparation parameters affect the crystallinity and the orientation of the phthalocyanines.
Received: 16 January 2002 / Accepted: 11 February 2002 / Published online: 3 May 2002
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ID="*"Corresponding author. Fax: +1-919/515-7331, E-mail: harald_ade@ncsu.edu
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ID="**"Present address: Southern Illinois University, Physics, Mailcode 4401, Carbondale, IL 62901, USA 相似文献
16.
17.
A. Di Lieto P. Minguzzi A. Pirastu S. Sanguinetti V. Magni 《Applied physics. B, Lasers and optics》2002,75(4-5):463-466
A Nd:YVO4 laser, end-pumped by a fiber-coupled diode-laser array, generates 7.3 W of output power at 1342 nm, the highest so far reported
for this host crystal. The slope efficiency is 40% and the output-beam divergence is close to the diffraction limit. An important
point in attaining such results is the choice of crystals with low Nd concentration.
Received: 16 July 2002 / Published online: 25 October 2002
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ID="*"Corresponding author. Fax: +39-050/844333, E-mail: dilieto@df.unipi.it
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ID="**"Permanent address: Scuola Normale Superiore, Piazza dei Cavalieri 7, Pisa, Italy 相似文献
18.
X.H. Liu Z.G. Liu Y.P. Wang T. Zhu J.M. Liu 《Applied Physics A: Materials Science & Processing》2003,76(2):197-199
Mainly [115]-oriented SrBi2Ta2O9 (SBT) films were prepared on GaAs(100) substrates with TiO2 buffer layers. Both the SBT films and the TiO2 buffer layers were deposited by pulsed laser deposition (PLD) using a KrF excimer laser. The depth profile of the constituent
elements observed by Auger electron spectrometry (AES) shows no remarkable diffusion at both the interfaces between SBT and
TiO2 and between TiO2 and the GaAs substrate. The electrical characteristics of the Pt/SBT/TiO2/GaAs(100) structures show a ferroelectric hysteresis loop with a small remanent polarization (∼0.5 μC/cm2).
Received: 1 March 2002 / Accepted: 3 March 2002 / Published online: 10 September 2002
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ID="*"Corresponding author. Fax: +86-25/3595535, E-mail: xhliu81@hotmail.com
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ID="**"Present address: Data Storage Institute, DSI Building, 5, Engineering Drive 1 (off Kent Ridge Crescent, NUS) 117608
Singapore 相似文献
19.
J. Luque R.J.H. Klein-Douwel J.B. Jeffries G.P. Smith D.R. Crosley 《Applied physics. B, Lasers and optics》2002,75(6-7):779-790
Absolute number densities of the CH radical were determined in a partially premixed methane/air flame (equivalence ratio was
1.36) at atmospheric pressure by exciting a predissociating level via the CH B–X(1,0) transition using a quasi-linear laser-induced
fluorescence scheme. The peak number density was (1.0±0.4)×1013 cm-3 or 2.4±1 ppm at 1900 K, with a flame-front width of 250 μm (FWHM). Rotational energy transfer must be considered for correct
laser-induced fluorescence signal interpretation. Competition between optical pumping and rotational relaxation in both excited
and ground states produces a signal that varies almost linearly with laser pulse energy even for large pumping rates. For
these conditions, the population of the initial ground-state rotational level is depleted by optical pumping, and rotational
energy transfer collisions rapidly repopulate the level during the laser pulse. Deviations from linear behavior are less than
20%. The effects of spatial resolution and polarization of the fluorescence on the absolute measurements are also discussed.
Received: 27 March 2002 / Revised version: 22 August 2002 / Published online: 15 November 2002
RID="*"
ID="*"Present address: Lam Research Corporation, Fremont, CA 94538, USA
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ID="**"Present address: Mechanical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
RID="***"
ID="***"Present address: Mechanical Engineering Dept., Stanford University, Stanford CA 94305, USA
RID="****"
ID="****"Corresponding author. Fax: +1-650/859-6196, E-mail: smith@mplvax.sri.com 相似文献
20.
High-resolution electron microscopy of individual metallofullerene molecules on the dipole orientations in peapods 总被引:1,自引:0,他引:1
K. Suenaga T. Okazaki K. Hirahara S. Bandow H. Kato A. Taninaka H. Shinohara S. Iijima 《Applied Physics A: Materials Science & Processing》2003,76(4):445-447
Electron microscopy with atomic sensitivity enables us to obtain a direct image of the intra-molecular structure of metallofullerenes
encapsulated inside single-walled carbon nanotubes. By a comparison of high-resolution images with a simulation to extract
the relative atom positions for encaged metal atoms in each molecule, the distribution of the molecular orientations and interactions
between adjacent molecules in metallofullerene peapods have been statistically analyzed. The results are suggestive of strong
interactions between fullerene–fullerene and fullerene–tube in peapods at room temperature.
Received: 10 October 2002 / Accepted: 25 October 2002 / Published online: 10 March 2003
RID="*"
ID="*"Corresponding author. Fax: +81-298/61-6310, E-mail: suenaga-kazu@aist.go.jp 相似文献