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1.
L.-W. Yin M.-S. Li J.-J. Cui Y.-J. Song F.-Z. Li Z.-Y. Hao 《Applied Physics A: Materials Science & Processing》2001,73(5):653-657
For understanding the mechanism of diamond growth at high temperature–high pressure (HTHP) from a metallic catalyst–graphite
system, it is of great interest to perform atomic force microscopy (AFM) experiments, which provide a unique technique different
from that of normal optical and electronic microscopy studies, to study the topography of HTHP as-grown diamond single crystals.
In the present paper, we report first AFM results on diamond single crystals grown from a Fe-Ni-C system at HTHP to reveal
the growth mechanism of diamond single crystals at HTHP. AFM images for as-grown diamond samples show dark etch pits on the
(111) surface, indicating dislocations. Some fine particles about 100–300 nm in dimension were directly observed on the (100)
diamond surface. These particles are believed to have been formed through transition of graphite to diamond under the effect
of the catalyst and to have been transported to the growing diamond surface through a metallic thin film by diffusion. The
roughness of the (100) diamond surface is found to be about several tens of nanometers through profile analysis. The diamond
growth at HTHP, in a sense, could be considered as a process of unification of these fine diamond particles or of carbon-atom-cluster
recombination on the growing diamond crystal surface. Successive growth interlayer steps on the (111) diamond surface were
systemically examined. The heights of the growth interlayer steps were measured by sectional analysis. It was shown that the
heights of the growth interlayer steps are quite different and range from about 10 to 25 nm. The source of the interlayer
steps might be dislocations. The diamond-growth mechanism at HTHP could be indicated by the AFM topography of the fine diamond
particles and the train-growth interlayer steps on the as-grown diamond surfaces.
Received: 29 March 2001 / Accepted: 20 August 2001 / Published online: 2 October 2001 相似文献
2.
Two-photon-excited luminescence (TEL) spectra have been recorded in the blue (400–500 nm) and near-ultraviolet (300–400 nm)
ranges for diamond particles with 4 nm average size, which were obtained by detonation synthesis from explosives. The observed
TEL bands are attributed, by comparing the obtained spectra with the impurity luminescence spectra in large diamond crystals,
to N2 and N3 defects associated with the presence of nitrogen impurities in diamond. The TEL spectra presented are found to have certain
distinguishing features: short-wavelength shift of the maximum and changes in the shape and width of the spectral bands for
ultradispersed diamond compared with the spectrum in bulk crystals.
Fiz. Tverd. Tela (St. Petersburg) 41, 1110–1112 (June 1999) 相似文献
3.
N. A. Poklonskii T. M. Lapchuk V. G. Baev G. A. Gusakov 《Journal of Applied Spectroscopy》2006,73(1):5-9
We have studied the electron spin resonance (ESR) of a 0.59 carat synthetic diamond single crystal at room temperature. The
crystal was grown on a “split-sphere” apparatus in the Fe-Ni-C system by the temperature gradient method. After high-temperature/high-pressure
treatment of the diamond, it was observed that as the microwave power supplied to the sample increased from 70 μW to 70 mW
in an H102 cavity, the ESR signal from the P1 center (a nitrogen atom substituting for carbon at a lattice point of the diamond crystal:
C-form nitrogen) is inverted. In the original diamond (before high-temperature/high-pressure treatment), no inversion of the
ESR signal was observed.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 9–12, January–February, 2006. 相似文献
4.
A. N. Obraztsov I. Yu. Pavlovskii H. Okushi H. Watanabe 《Physics of the Solid State》1997,39(10):1594-1598
Photoacoustic spectroscopy is used to study optical absorption in diamond powders and polycrystalline films. The photoacoustic
spectra of diamond powders with crystallite sizes in the range from ∼100 μm to 4 nm and diamond films grown by chemical vapor deposition (CVD) had a number of general characteristic features corresponding
to the fundamental absorption edge for light with photon energies exceeding the width of the diamond band gap (∼5.4 eV) and
to absorption in the visible and infrared by crystal-structure defects and the presence of non-diamond carbon. For samples
of thin (∼10 μm) diamond films on silicon, the photoacoustic spectra revealed peculiarities associated with absorption in the silicon substrate
of light transmitted by the diamond film. The shape of the spectral dependence of the amplitude of the photoacoustic signal
in the ultraviolet indicates considerable scattering of light specularly reflected from the randomly distributed faces of
the diamond crystallites both in the polycrystalline films and in the powders. The dependence of the shape of the photoacoustic
spectra on the light modulation frequency allows one to estimate the thermal conductivity of the diamond films, which turns
out to be significantly lower than the thermal conductivity of single-crystal diamond.
Fiz. Tverd. Tela (St. Petersburg) 39, 1787–1791 (October 1997) 相似文献
5.
A. V. Khomich N. A. Poklonskii N. M. Lapchuk R. A. Khmel’nitskii V. A. Dravin S. Munkhtsetseg 《Journal of Applied Spectroscopy》2007,74(4):537-543
We used IR spectroscopy and electron spin resonance (ESR) to investigate defect reconstruction processes occurring in diamond
crystals due to their implantation with H+ ions with energies of 65–350 keV and subsequent isochronous annealing in the temperature range 250–1550°C. We found that
most of the hydrogen in diamonds implanted with protons is in an IR-inactive state. Magnetic hysteresis related to radiation
defects in diamond is observed for the first time at room temperature using ESR.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 485–490, July–August, 2007. 相似文献
6.
Lyda La-Torre-Riveros Emely Abel-Tatis Adrián E. Méndez-Torres Donald A. Tryk Mark Prelas Carlos R. Cabrera 《Journal of nanoparticle research》2011,13(7):2997-3009
With the aim of developing dimensionally stable-supported catalysts for direct methanol fuel cell application, Pt and Pt–Ru
catalyst nanoparticles were deposited onto undoped and boron-doped diamond nanoparticles (BDDNPs) through a chemical reduction
route using sodium borohydride as a reducing agent. As-received commercial diamond nanoparticles (DNPs) were purified by refluxing
in aqueous nitric acid solution. Prompt gamma neutron activation analysis and transmission electron microscopy (TEM) techniques
were employed to characterize the as-received and purified DNPs. The purified diamond nanoparticulates, as well as the supported
Pt and Pt–Ru catalyst systems, were subjected to various physicochemical characterizations, such as scanning electron microscopy,
energy dispersive analysis, TEM, X-ray diffraction, inductively coupled plasma-mass spectrometry, X-ray photoelectron spectroscopy,
and infrared spectroscopy. Physicochemical characterization showed that the sizes of Pt and Pt–Ru particles were only a few
nanometers (2–5 nm), and they were homogeneously dispersed on the diamond surface (5–10 nm). The chemical reduction method
offers a simple route to prepare the well-dispersed Pt and Pt–Ru catalyst nanoparticulates on undoped and BDDNPs for their
possible employment as an advanced electrode material in direct methanol fuel cells. 相似文献
7.
Bernard Piechal Jens W. Tomm Artem Bercha Witold Trzeciakowski Martin Reufer Alvaro Gomez-Iglesias 《Applied Physics A: Materials Science & Processing》2009,97(1):179-184
The hydrostatic pressure behavior of red-emitting diode lasers packaged on Si, AlN, and diamond submounts is studied in the
0–2 GPa range by emission and photocurrent spectroscopy. Photocurrent spectroscopy allows for simultaneous measurement of
the InGaP quantum well and (Al0.5Ga0.5)0.5In0.5P waveguide. A broadening of the absorption edge of the waveguide is observed for all devices and explained by the pressure-induced
direct-to-indirect transition in this material. For the QW resonance, distinct differences are observed for differently packaged
devices. Thus, very low pressure tuning rates are demonstrated for devices packaged on diamond and AlN submounts and explained
by the presence of shear strain components. Consistently we find the device packaged on Si to be least affected by the strain
caused by the pressure cycling. 相似文献
8.
B. Kołkowski 《Applied Physics A: Materials Science & Processing》1979,20(4):305-312
An analysis of possible transformations of moments of force by a diamond lattice has been made. The conditions of resonance
transformations of moments of force by this lattice have been found. The dynamics symmetry of the diamond lattice has been
determined in terms of the Shubnikov group Fd3m'.
Besides, it has been found that resonance librationally deformed configurations are oneperiodic and have cores 〈110〉 two times
more deformed than the surrounding area. As a result of the action of resonance phonons of the librational mode it is possible
to generate a new kind of defects-bidislocations with Burgers vector components+[110]/2 and −[110]/2.
It has been shown that bidislocations can play an essential role in plastic deformation of a diamond lattice and other related
lattices. 相似文献
9.
Ion-implanted buried layer in diamond as a source of ballistic phonons at liquid-helium temperatures
T. I. Galkina A. I. Sharkov A. Yu. Klokov M. M. Bonch-Osmolovskii R. A. Khmel’nitskii V. A. Dravin A. A. Gippius 《JETP Letters》1996,64(4):298-300
It is shown that an approximately 150 nm thick ion-implanted buried layer in diamond and excited by a pulsed laser at wavelength
λ=337 nm is a source of nonequilibrium acoustic phonons propagating ballistically through the diamond sample at temperatures
∼2 K.
Pis’ma Zh. éksp. Teor. Fiz. 64, No. 4, 270–272 (25 August 1996) 相似文献
10.
In this study, the optical properties as well as mechanical and electrical degradation of low-density polyethylene (LDPE)/polypropylene
fiber (PP fiber) (10–50% PP fiber), polypropylene (PP)/PP fiber (10–50% PP fiber), and LDPE/diamond (0.1–3% diamond) blends,
which are prepared by hot pressing method, with changing thicknesses ranging from 30 to 225 μm, are compared. The spectra,
in the wavelength range 200–2500 nm, are examined. Based on optical absorption spectra obtained, Tauc graphs are plotted.
Determined values of the direct optical energy gap (E
d
opt
), the indirect optical energy gap (E
i
opt
), the width of the band (ΔE), and ultraviolet transmittance (TUV) are listed. The direct E
d
opt
and indirect E
i
opt
values for organic blends are in the range of 3.10–3.17 eV and 1.52–2.99 eV; for inorganic blends they are 1.80–4.13 eV and
1.55–4.7 eV respectively. The electrical strength (ε) and the mechanical tension (σ) have been investigated, and graphs (the
dependence of the electrical life time log τε on ε) are given. The experimental results are analyzed from the viewpoint of the validity of the thermofluctuation theory.
LDPE and LDPE/0.5% diamond composite parameters consecutively changed: σ from 68 to 82 MPa, ε from 60·106 to 85·106 V/m, mechanical lifetime τσ from 10 to 1.5·105 sec, electrical lifetime τε from 2· 103 to 2·105 sec, and structure-sensitive parameters γ and χ — from 1.48 to 1.18 (J)MPa/mole and from 0.97 to 0.70 (J)Vm−1/mole respectively. The values of mechanical and electrical durability were observed to increase by 20 and 41%, respectively,
for LDPE/0.5% diamond composite.
Published in Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 677–683, September–October, 2007. 相似文献
11.
V. V. Brazhkin A. G. Lyapin R. N. Voloshin S. V. Popova Yu. A. Klyuev A. M. Naletov S. C. Bayliss A. V. Sapelkin 《JETP Letters》1999,69(11):869-875
The results of an investigation of the transformation of C60 fullerite to diamond under pressure through intermediate three-dimensionally polymerized and amorphous phases are reported.
It is found that treatment of fullerite C60 at pressures 12–14 GPa and temperatures ∼1400°C produces a nanocrystalline graphite-diamond composite with a concentration
of the diamond component exceeding 50%. At lower temperatures (700–1200°C) nanocomposites consisting of diamondlike (sp
3) and graphitic (sp
2) amorphous phases are formed. The nanocomposites obtained have extremely high mechanical characteristics: hardness comparable
to that of best diamond single crystals and fracture resistance two times greater than that of diamond. Mechanisms leading
to the transformation of C60 fullerite into diamond-based nanocomposites and the reasons for the high mechanical characteristics of these nanocomposites
are discussed.
Pis’ma Zh. éksp. Teor. Fiz. 69, No. 11, 822–827 (10 June 1999) 相似文献
12.
T. Uesaka V. P. Ladygin L. S. Azhgirey Yu. V. Gurchin A. Yu. Isupov K. Itoh M. Janek J. -T. Karachuk T. Kawabata A. N. Khrenov A. S. Kiselev V. Kizka J. Kliman V. A. Krasnov A. N. Livanov Y. Maeda A. I. Malakhov V. Matoucek M. Morhac S. Nedev S. Rangelov S. G. Reznikov S. Sakaguchi H. Sakai Y. Sasamoto K. Sekiguchi K. Suda I. Turzo T. A. Vasiliev T. Wakui 《Physics of Particles and Nuclei Letters》2006,3(5):305-311
A new high-energy beam polarimeter is proposed for Nuclotron, which uses the Internal Target Station (ITS). This polarimeter
based on a measurement of asymmetry for the d–p elastic scattering will allow one to measure simultaneously both vector and tensor components of deuteron beam polarization.
For this purpose an analyzing powers measurement for the d–p elastic scattering at energies T
d = 0.88–2 GeV is proposed. The precise measurements of the deuteron analyzing powers over the energy range T
d = 300–2000 MeV can give an irreplaceable clue to the study of the spin dependence of three nucleon forces.
The text was submitted by the authors in English. 相似文献
13.
L.W. Yin M.S. Li Y.X. Liu D.S. Sun F.Z. Li G.L. Geng Z.Y. Hao 《Applied Physics A: Materials Science & Processing》2001,72(4):487-490
Cubic boron nitride (c-BN) crystals about 0.1–0.3 mmin dimension were treated with iron carbide powders (high purity 99%)
with size of 80–100 mesh at a high temperature of 1620 K and a high pressure of 5.2 GPa. It was found that hetero-epitaxial
diamond films have been grown on the c-BN from iron carbide. The formation of dia-mond films on the cubic boron nitride can
be confirmed by laser Raman spectra, face scan of elements and reflective high-energy electron diffraction. It was suggested
that diamond films could be epitaxially formed on the c-BN through decomposition of iron carbide. This approach provides a
possible and very effective way to realize hetero-epitaxial growth of homogeneous and large-area diamond films on c-BN, which
is different from the conventional technique using a chemical vapor deposition method.
Received: 20 December 2000 / Accepted: 9 January 2001 / Published online: 28 February 2001 相似文献
14.
Laser polishing of diamond plates 总被引:5,自引:0,他引:5
S.M. Pimenov V.V. Kononenko V.G. Ralchenko V.I. Konov S. Gloor W. Lüthy H.P. Weber A.V. Khomich 《Applied Physics A: Materials Science & Processing》1999,69(1):81-88
Results are reported on laser polishing of 150–400-μm-thick free-standing diamond films with either a copper vapor laser (510 nm
wavelength) or an ArF excimer laser (193 nm wavelength). Studies were focused on three particular goals. First, we aimed at
a choice of optimum conditions for laser polishing of thick diamond films. It was shown that the laser polishing conditions
and the resulting surface roughness were controlled by varying the angle of incidence of a scanning laser beam and by polishing
time. Second, the laser ablation technique was applied to remove a defective layer from the “substrate” side of the diamond
plates in order to reduce optical losses due to absorption in this layer. Third, the structure of the laser-graphitized diamond
surface was studied using UV, visible, and IR optical spectroscopy techniques in the course of the “step-by-step” oxidative
removal of the graphitic layer with increasing temperature of the oxidation in ambient air. Once the graphitic layer was removed,
the optical transmission in the UV-visible-IR spectral range of the diamond films polished under optimum conditions was measured
and compared with the optical transmission of the mechanically polished diamond films. It was shown that the optical quality
(in the long-wave infrared region) of the laser-polished diamond plates was sufficient to reach the transmittance value very
close to the theoretical limit.
Received: 20 October 1998 / Accepted: 8 March 1999 / Published online: 5 May 1999 相似文献
15.
Spectral and kinetic characteristics of the pulsed cathodoluminescence of a natural IIa-type diamond
E. I. Lipatov V. M. Lisitsyn V. I. Oleshko V. F. Tarasenko 《Russian Physics Journal》2007,50(1):52-57
Emission spectra and decay kinetics of pulsed cathodoluminescence of a natural IIa-type diamond sample are investigated in
the spectral range 340–680 nm. The luminescence of the vibronic N3-system and band A are observed. The N3-system is dominant
on a nanosecond scale and has a 415.2-nm zero-phonon line with phonon replicas in the range 430–460 nm. The decay time for
the N3 system is found to be 30–50 ns. Structureless band A is observed on a millisecond scale; it has a maximum at 460 nm
and a decay time of 8.5–8.8 ms.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 53–57, January, 2007. 相似文献
16.
For more than a century Liesegang patterns – self-organized,
quasi-periodic structures occurring in diffusion-limited chemical reactions
with two components – have been attracting scientists. The pattern formation
can be described by four basic empirical laws. In addition to many experiments,
several models have been devised to understand the formation of the bands and
rings. Here we review the most important models and complement them with
detailed three-dimensional lattice-gas simulations. We show how the mean-field
predictions can be reconciled with experimental data by a redefinition of
the distances suggested by our lattice-gas simulations. 相似文献
17.
A. M. Efimov A. I. Ignat’ev N. V. Nikonorov E. S. Postnikov 《Optics and Spectroscopy》2011,111(3):426-433
We have measured the UV absorption spectra of photothermorefractive glasses of the system Na2O-ZnO-Al2O3-NaF-SiO2 doped by cerium oxide in the range of (2.8–5.0) × 104 cm−1 (360–200 nm). The spectra have been processed by the method of dispersion analysis based on the analytical convolution model
for the complex dielectric function of glasses. We show that the absorption band centered at 3.3 × 104 cm−1 (∼303 nm) that is attributed to the transition 2F
5/2 → 5d in the Ce3+ ion, is an envelope of three spectral components. The broad absorption range (3.5–4.7) × 104 cm−1 (200–270 nm) that is commonly interpreted as a charge transfer band of the Ce(IV) valence state, is an envelope of at least
three spectral components. 相似文献
18.
Konstantin Iakoubovskii 《Central European Journal of Physics》2009,7(4):654-662
This review covers recent advances in superconductivity of diamond, Si, SiC, group III–V and II–IV semiconductors, metal-intercalated
graphite and fullerites. The results are critically analyzed and prospects are given for future research directions. In particular,
it is argued that the highest transition temperatures of ∼9 K in diamond and 11.5 K in CaC6 can further be enhanced and that no reliable evidence exists yet for superconductivity in III-V semiconductors.
相似文献
19.
The pressure dependence of lattice constants of 13C-enriched diamond and diamond of natural isotopic composition have been studied by using x-ray synchrotron radiation and
the imaging plate technique. The compression curves reveal features which indicate an inversion of the isotope effect at high
pressure.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 2, 73–77 (25 January 1996)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
20.
A. N. Obraztsov I. Yu. Pavlovskii V. G. Ral’chenko H. Okushi H. Watanabe 《Technical Physics》1999,44(4):438-442
A new method of determining the heat-conducting properties of diamond films is proposed, based on the photoacoustic effect.
This method is used to study diamond polycrystalline films grown on silicon by chemical vapor deposition in a microwave discharge
plasma. The thermal conductivity obtained was approximately half that for single-crystal diamond.
Zh. Tekh. Fiz. 69, 97–101 (April 1999) 相似文献