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1.
V. P. Rotshtein Yu. F. Ivanov A. B. Markov D. I. Proskurovskii K. V. Oskomov V. V. Uglov S. N. Dub Y. Pauleau I. A. Shulepov 《Russian Physics Journal》2005,48(12):1221-1228
The surface topography, chemical composition, microstructure, nanohardness, and tribological characteristics of a Cu (film,
512 nm)-stainless steel 316 (substrate) system subjected to pulsed melting by a low-energy (20–30 keV), high-current electron
beam (2–3 μs, 2–10 J/cm2) were investigated. The film was deposited by sputtering a Cu target in the plasma of a microwave discharge in argon. To
prevent local exfoliation of the film due to cratering, the substrate was multiply pre-irradiated with 8–10 J/cm2. On single irradiation, the bulk of the film survived, and a diffusion layer containing the film and substrate components
was formed at the interface. The thickness of this layer was 120–170 nm irrespective of the energy density. The diffusion
layer consisted of subgrains of γ-Fe solid solution and nanosized particles of copper. In the surface layer of thickness 0.5–1 μm, which included the copper
film quenched from melt and the diffusion layer, the nanohardness and the wear resistance nonmonotonicly varied with energy
density, reaching, respectively, a maximum and a minimum in the range 4.3–6.3 J/cm2. As the number of pulsed melting cycles was increased to five in the same energy density range, there occurred mixing of
the film-substrate system and a surface layer of thickness ∼2 μm was formed which contained ∼20 at. % copper. Displacement
of the excess copper during crystallization resulted in the formation of two-phase nanocrystal interlayers separating the
γ-phase grains.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 6–13, December, 2005. 相似文献
2.
The orientational dependence for different groups of secondary electrons — quasi-elastically scattered, inelastically reflected
with excitation of a plasmon and with ionization of the core level M
4.5, and the Auger electrons M
4.5
VV — are measured in the primary electron energy range 0.6–1.5 keV. The data are obtained for a Nb (100) single crystal by varying
the azimuthal angle of incidence of the primary beam, with complete collection of secondaries. A relationship is established
between the processes of focusing and defocusing of the electrons that have penetrated into the crystal in the 〈110〉 and 〈133〉
directions, which differ substantially in the atomic packing density. Specific details of the Auger orientation effect, due
to the focusinginduced variation of the flux density of the reflected electrons, are identified and explained. The contributions,
both of anisotropy of ionization of the core level and of variation of the backscattering intensity, to the angular dependence
of Auger emission and reflection with ionization loss are estimated. The possibilities of using such orientational dependences
for an element-sensitive analysis of the local atomic structure of surfaces are assessed.
Zh. Tekh. Fiz. 67, 117–123 (August 1997) 相似文献
3.
The electron yield per ion charge-state γ/q was measured for emission of electrons from clean polycrystalline gold induced due to impact of Ta
q+ (11≤q≤41) ions with kinetic energy per chargeE
i/q from 15 keV/q to 150 keV/q. The dependence of γ on angle of incidence was analyzed with use of relation γ(ϑ)=γ0 cos−f
ϑ. The fitting of experimental data gives a range of γ0/q from 1 to 1.75 for Ta13+ and from 1.5 to 1.73 for Ta39+. The dependence of γ0/q onq andE
i is discussed with respect to measurement of ion currents emitted from laser-produced plasmas with an ion collector with unsuppressed
secondary electron emission.
This work was supported by the Division of Chemical Sciences, Office of Basic Energy Sciences, Office of Energy Research,
U.S. Department of Energy, and by grant A1010819 from the Grant Agency of the Academy of Sciences of the Czech Republic. 相似文献
4.
A. V. Kukhta 《Journal of Applied Spectroscopy》2006,73(6):879-885
Electronic and vibrational electron energy loss spectra are studied on ultrathin Alq3 films for different electron energies, thicknesses, and temperatures of the film. The shape of the spectrum and the position
of the lines are very weakly dependent on the film thickness, indicating weak interaction between the adsorbed molecules and
the platinum substrate. The temperature dependence of the vibrational bands is weak. The positions of the triplet and singlet
maxima are close to gas-phase and thin-film data obtained for high electron energy. Interference of electrons is observed
in measuring the energy loss spectra. The effect of dipole and collisional excitation mechanisms is shown. From the similarity
between the energy loss spectra it follows that the nature of the interaction between low-energy electrons and organic materials
is the same in gas and thin-film phases, and likewise for the characteristics of the motion of the electrons.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 786–791, November–December, 2006. 相似文献
5.
F. P. Heßberger 《Physics of Atomic Nuclei》2007,70(8):1445-1451
Radioactive decay from the ground state or isomeric states has been investigated for a series of nuclei in the region of Z = 100–106 by means of α–γ—or evaporation residue-(γ, conversion electron)—measurements in prompt and delayed coincidence. Systematic trends in single-particle level energies
in N = 145–151 odd-even isotones could be extended up to Z = 104, while an energy systematics of lowlying Nilsson levels in odd-mass einsteinium isotopes was established. Information
on nuclear levels at E* > 500 keV was obtained from the decay study of isomeric states in 251−255No.
The text was submitted by the author in English. 相似文献
6.
A. K. Panchal D. K. Rai Meril Mathew C. S. Solanki 《Journal of nanoparticle research》2011,13(6):2469-2473
40 alternate a-Si/SiN
x
multilayer are incorporated as an absorber layer in a p–i–n solar cell. The device is fabricated using hot-wire chemical
vapor deposition (HWCVD) technique. The structure of the multilayer film is examined by high resolution transmission electron
microscopy (HR-TEM) which shows distinct formation of alternate a-Si and SiN
x
layers. The a-Si and SiN
x
layers have thickness of ~3.5 and 4 nm, respectively. The photoluminescence (PL) of multilayer film shows bandgap energy
of ~2.52 eV, is larger than that of the c-Si and a-Si. Dark and illuminated current–voltage (I–V) characterization of the ML films shows that these ML are photosensitive. In the present work, it is seen that the p–i–n
structure with i-layer as ML quantum well (QW) structures show photovoltaic effect with relatively high open-circuit voltage
(V
OC). The increment of bandgap energy in PL and high V
OC of the device is attributed to the quantum confinement effect (QCE). 相似文献
7.
Magno V. T. Machado 《The European Physical Journal C - Particles and Fields》2009,59(4):769-776
Using the high-energy color-dipole formalism, we study the coherent and incoherent nuclear DVCS process, γ
*
A→γ
X, in the small-x regime. We consider simple models for the elementary dipole–hadron scattering amplitude that capture the main features of
the dependence on atomic number A, on energy and on momentum transfer t. Using the amplitudes obtained we make predictions for the nuclear DVCS cross section at the photon level in collider kinematics. 相似文献
8.
The surface tension of ionic liquids is studied according to phenomenological scaling and the law of corresponding states.
The reduced coordinates γ*–T*, where γ* represents the reduced surface tension and T* is the reduced temperature, are introduced for the prediction of the surface tension from the melting point up to boiling
point. It has been shown that the correlation can be expressed as a unique straight-line plot with a linear correlation coefficient
of 0.984 that requires only the melting and boiling point parameters and can predict the surface tension accurately. 相似文献
9.
S. A. Pikin E. I. Demikhov E. S. Pikina M. V. Gorkunov 《Journal of Experimental and Theoretical Physics》1997,84(3):506-515
The dynamics of spontaneous polarization switching of the ferroelectric smectic C* in a variable electric field are examined theoretically and experimentally with the help of polarized light scattering.
The observed effect of quasiresonant scattering both in freely suspended smectic films and in ordinary electro-optical cells
is interpreted within the framework of the nonlinear model of isolated movable kinks in the director orientation distribution.
It is shown that the maximum of the scattering intensity at the characteristic frequency of the applied electric field disappears
at low temperatures and for small thicknesses of the smectic film. The dependence of the “resonant” frequency on the electric
field amplitude, the proximity to the phase transition temperature, the film thickness and thickness of the ferroelectric
domains, and also various material parameters is found. Estimates are made of such important characteristics as the dielectric
anisotropy, viscosity, and elasticity of the smectic films. The effect of film thickness on the density distribution of the
polar anisotropy energy in the film and on the corresponding shape of the moving orientation front within the film are discussed.
Zh. éksp. Teor. Fiz. 111, 919–937 (March 1997) 相似文献
10.
Lin T. Shang L. Y. Zhou W. Z. Meng X. J. Sun J. L. Yu G. Guo S. L. Chu J. H. 《Applied Physics A: Materials Science & Processing》2012,106(3):703-707
The surface transport properties of naturally oxidized p-type Hg0.776Cd0.224Te thin film were investigated in the magnetic-field region 0–14 T and in the temperature region 8–300 K. The Hall electron
concentration increases with temperature, while the surface concentration of the two-dimensional electrons in the naturally
oxidized surface, calculated by Shubnikov–de Haas oscillations, decreases as temperature increases at temperatures below 20 K.
The contradiction and the extraordinary quantum Hall filling factors are accounted for by assuming extra bulk-like electrons
in the surface region, which dominate the surface transport properties at temperatures over 8 K. 相似文献
11.
Using the imaginary time method, we study the structure of the perturbation series for the hydrogen atom in electric ℰ and
magnetic ℋ fields. It is shown that there is a “critical” value of the ratio γ=ℋ|ℰ at which the perturbation series for the ground state changes from having a fixed sign (for γ<γ
c
) to having a variable sign (for γ>γ
c
). This conclusion is confirmed by direct higher-order perturbation calculations. The change in the asymptotic regime is explained
by competition among the contributions of the various complex trajectories that describe the subbarrier motion of the electrons.
Here the parameter γ
c
depends on the angle θ between the electric and magnetic fields.
Zh. éksp. Teor. Fiz. 113, 2047–2055 (June 1998) 相似文献
12.
The electronic spectrum in a cylindrical CdS/β-HgS semiconductor heterosystem of the quantum wire type located in an H2O dielectric medium is investigated. In the energy interval where the levels of both potential wells merge, there is a repulsion
effect on the levels (a “bottleneck” effect). The nonmonotonic dependence of the electron and hole spectra on the thickness
of the β-HgS film means that in experiments there is an instability of the energy position of the exciton lines in a certain
frequency range.
Chernovits State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 79–85, May, 1997. 相似文献
13.
M. M. Kirillova I. D. Lobov V. M. Maevskii L. V. Nomerovannaya A. A. Makhnev G. A. Bolotin F. A. Pudonin 《Journal of Experimental and Theoretical Physics》1997,85(5):925-933
The optical and magneto-optical properties of multilayered film samples of the Fe/Cu system prepared by high-frequency sputtering
on an Si(100) substrate are studied by ellipsometry and by measuring the equatorial Kerr effect (the δ
p effect) in the spectral range 0.25–7 μm. The optical characteristics, the plasma frequency ω
p and the relaxation frequency γ
0 of the conduction electrons, and the δ
p effect are found as functions of the modulation period D=12.5–100 Å. Anomalous behavior of the optical and magneto-optical characteristics is discovered in short-period Fe/Cu structures.
The results are discussed within a phenomenological theory of optical and magneto-optical properties for layered structures.
Several factors, such as the indirect exchange interaction between the iron layers, the presence of a transition layer on
the internal boundaries, the possible “magnetizing” of copper, and the formation of an fcc iron phase in the thin layers,
are taken into account in the analysis of the experimental data.
Zh. éksp. Teor. Fiz. 112, 1694–1709 (November 1997) 相似文献
14.
The dispersion of magnetoplasma excitations in two-dimensional electron systems in a strong parallel magnetic field has been
studied. A considerable increase in the electron cyclotron mass with an increase in the parallel component of magnetic field
has been detected. It has been found that the cyclotron mass increment is a quadratic function of the magnetic field parallel
to the interface. It has been shown that the mass anisotropy of 2D electrons induced by the parallel magnetic field reaches
nearly 2.5 in B
‖ = 7 T. The energy of space quantization of the electron in the quantum well has been estimated from the magnetic field dependence
of the anisotropy. 相似文献
15.
E. Glickman D. Fuks N. Frage S. Barzilai N. Froumin 《Applied Physics A: Materials Science & Processing》2012,106(1):181-189
The experiments show that the alloying liquid In with only (0.1–0.5) at% Ti dramatically reduces the equilibrium contact angle
Θ
∞ formed by In on the surface of CaF2. The aim of this paper is to clarify whether this practically important and conceptually challenging effect can be explained
solely by Ti adsorption at the F-terminated solid–liquid interface without resorting to any other Ti-induced effect. The combination
of ab initio calculations and regular solution approximation was proposed for finding the binding energy, ΔE
Ti of Ti adatom with the interface “CaF2/liquid solutions In–Ti.” With thus obtained ΔE
Ti=1.16 eV, we calculated from the Shishkovsky isotherm the reduction in the solid–liquid interface energy, Δγ
SL induced by Ti adsorption from liquid In with various Ti concentration, C. It was found that Δγ
SL(C) dependence demonstrated close inverse correspondence with Θ
∞(C) and that the theory fitted very well all available experimental data on the concentration and temperature dependence of
Δγ
SL. It was concluded that the Ti adsorption effect is large enough to account for the observed wetting improvement. The proposed
multiscale modeling approach to the role of adsorption in wetting can be applied also to other nonreactive systems “liquid
metal–ceramics” where the substrate determines the surface density of the adsorption sites for the active element. 相似文献
16.
H. Beckmann G. Bergmann 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,13(3):495-502
Sandwiches made from Fe and Cs films are investigated as a function of the magnetic field and the Cs thickness. Conduction
electrons which cross from the Fe to the Cs are marked by a drift velocity component perpendicular to the electric field.
The anomalous Hall effect in the Fe provides this “non-diagonal” kick to the electrons that cross from the Fe into the Cs.
The ballistic propagation of the conduction electrons can be monitored as a function of the Cs film thickness. The free propagation
into the Cs is measured in terms of the non-diagonal conductance Lxy which we denote as the “induced anomalous Hall conductance”L
xy
0. For a normal (non-magnetic) metal in contact with Fe, Lxy increases with the thickness of the normal metal until the film thickness exceeds (half) the mean free path of the conduction
electrons. For Cs on top of Fe the induced anomalous Hall conductance increases up to a Cs coverage of about 100 A, then,
in contrast to other non-magnetic metals, L
xy
0 decreases for larger Cs coverage and approaches zero. This behavior cannot be explained with the free electron model. The
strange behavior of the induced AHC in Cs films adds an even more challenging mystery to the already poorly understood properties
of thin Cs films. These results defy explanation in the free electron model.
Received 29 April 1999 and Received in final form 10 July 1999 相似文献
17.
Hosein Golmojdeh Mohammad Ali Zanjanchi Shabnam Sohrabnejad Jamal Mazloom Pejman Hojati‐Talemi 《X射线光谱测定》2014,43(3):180-185
In the current work, a thin film of bismuth vanadate was defined over a silicon substrate, and a calculative Monte Carlo approach was followed to achieve the best grazing‐exit angle to acquire compositional data from top few nanometers of surface. This strategy is very beneficial in order to increase X‐ray signals originated from surface and diminish the background X‐ray signals started off from the substrate. In this regard, grazing‐exit energy dispersive X‐ray spectroscopy can be considered as an accessible and economical analytical tool to investigate thin films and nano‐layers. The major advantage of this method is that just by applying a re‐arrangement in a scanning electron microscope, it can be used to study compositional properties of thin layers. In this contribution, a theoretical approach using Monte Carlo models was used to simulate the behavior of electron beams impinging onto BiVO4 nano‐layers with thickness of 50 nm and electron trajectories inside the film. Characteristic X‐rays and spatial energy distribution of the backscattered electrons were also calculated. Under grazing‐exit angle of around 0.5°, the best surface signal/background noise ratio was achieved. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
18.
A. S. Komolov 《Technical Physics》2004,49(5):630-634
Thin films of tri-oligo(phenylene-vinylene) end-terminated by di-butyl-thiole (tOPV) were thermally deposited in UHV on Ge(111)
substrates. The surface potential and the structure of unoccupied electron states (DOUS) located 5–20 eV above the Fermi level
(E
F) were monitored during the film deposition using an incident beam of low-energy electrons according to the total current
electron spectroscopy (TCS) method. The electronic work function of the surface changed during the film deposition until it
reached a stable value of 4.3±0.1 eV at a tOPV film thickness of 8–10 nm. Deposition of the tOPV under 3 nm led to the formation
of intermediate DOUS structures that were replaced by another DOUS structure along with an increase in the tOPV deposit thickness
up to 8–10 nm. The occurrence of the intermediate DOUS structure is indicative of a substantial reconfiguration of the electronic
structure of the tOPV molecules due to the interaction with the Ge(111) surface. Analysis of the TCS data allowed us to assign
the unoccupied electronic bands in tOPV located at 5.5–6.5 and 7.5–9.5 eV above the E
F as π* bands and at 11–14 and 16–19 eV above E
F as σ* bands. 相似文献
19.
O. V. Volkov V. E. Zhitomirskii I. V. Kukushkin K. von Klitzing K. Eberl 《JETP Letters》1996,64(10):774-779
A study is made of the temperature dependence of the magnetooscillations of the recombination radiation of 2D electrons from
the photoexcited size-quantization subband in an isolated GaAs/AlGaAs quantum well. It is shown that at high temperatures
(T>10 K) the period of the oscillations is determined by the ratio of the intersubband energy splitting and the sum of the electron
and hole cyclotron energies. It is found that as the temperature decreases (T<5 K), a new series of oscillations (with the same period but with a larger phase shift), which are associated with the appearance
of excitonic states under the Landau levels, appears.
Pis’ma Zh. éksp. Teor. Fiz. 64, No. 10, 719–724 (25 November 1996) 相似文献