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1.
Petrov M. P. Voitylov V. V. Klemeshev S. A. Trusov A. A. 《Optics and Spectroscopy》2011,111(5):832-840
We present the results of our experimental investigation of light scattering by polydisperse colloids of diamond and graphite.
The scattering is studied at a random orientation of particles and in an external radiofrequency electric field, which orients
particles along the strength. The average dimensions of particles in both colloids are close to each other and comparable
with the wavelength of the incident light. The shape of particles and the optical and electrooptical properties of diamond
and graphite colloids are significantly different. We analyze the polarization components of scattered light energy when the
light incident on the colloids is linearly polarized. We show that the quadrupole light scattering by isotropic diamond particles
has the main effect on angular dependences of depolarization of scattered light. For light scattering by anisotropic graphite
particles, the depolarization of scattered light is mainly determined by a particular feature of the dipole scattering of
particles. It is shown that, in both colloids, the orientational order of particles considerably reduces the depolarization
of light scattered by particles. We show that relative changes in the intensity and depolarization of scattered light, which
depend on the scattering angle and polarization direction of light, as well as on the parameters of particles, can be used
as a measure of electrooptical effects observed in colloids. 相似文献
2.
V. V. Voitylov P. I. Ivashchenko A. A. Trusov I. V. Altukhov 《Optics and Spectroscopy》2009,107(5):717-720
Results of an electrooptical study of a water solution of carbon nanotubes obtained using the catalytic method are presented.
It is shown that nanotubes, which anisotropically absorb light, are oriented in an electric field and create a pronounced
linear electric dichroism due to light absorption, rather than light scattering (as in the case of colloids with particles
with sizes close to that of nanotubes). An analysis of the relaxation dependences of the electric dichroism shows that nanotubes
deform, which are oriented in the electric field; in this case, the deformation sublinearly depends on the field amplitude
and reaches a limiting value. The relaxation dependence of the field-induced dichroism agrees with the autocorrelation function
of depolarized light scattered perpendicular to the incident light flux. 相似文献
3.
V. V. Vojtylov S. A. Klemeshev M. P. Petrov A. A. Trusov 《Optics and Spectroscopy》2013,114(3):432-439
We have presented the results of our investigations of relative changes in the intensity of light scattered by nanodisperse systems that are exposed to the action of an electric field. To orient particles of the systems under study, sinusoidal fields of variable amplitude and frequency from the radiofrequency range were used. We have examined aqueous polydisperse suspensions of diamond and graphite particles. The average sizes of particles in the two suspensions are close to each other and are comparable with the wavelength of the incident light. Graphite particles had the shape of disks, while polycrystalline diamond particles did not have a clearly pronounced shape. Investigations have been conducted not only in the regime of a stationary orientational order of particles in the field, but also in the course of forced and free relaxation of this order. For the graphite nanodisperse system, the normalized-in-amplitude dependences of observed electrooptical effects on the field strength almost do not depend on the scattering angle, whereas, for the diamond nanodisperse system, they considerably vary as this angle changes. Upon relaxation of the orientational order of particles, the time dependences of these effects in both systems change with varying scattering angle. We have compared field and time dependences of scattering-induced effects with analogous dependences of field-induced dichroism. 相似文献
4.
D. A. Zimnyakov 《Optics and Spectroscopy》2000,89(3):453-462
Based on phenomenological concepts of statistics of effective optical paths for multiple scattering of coherent radiation, an analysis is carried out of similarity effects observed for the dependences of statistical moments of the scattered field on the relaxation parameters with a dimension of reciprocal length. Within the framework of the diffusion approximation, expressions are obtained that describe the autocorrelation function of fluctuations of the scattered-field amplitude, the degree of polarization, and the normalized intensity of scattered light for media with a finite absorption length in the case of forward scattering of coherent radiation in a plane layer of an isotropic scattering medium. The results of the analysis show the similarity of the dependences of these quantities on the corresponding spatial scales. Experiments with model scattering media (aqueous suspensions of polystyrene spherical particles) supported the existence of similarity effects in multiple scattering. An experimental study was made of the relation between the characteristic depolarization length and the transport length for multiple scattering of coherent radiation in a plane layer. The effective value of the radiation diffusion coefficient providing the best agreement between the experimental and the calculated values of parameters of the scattered field is shown to be independent of the absorption coefficient of a medium. 相似文献
5.
V. Ya. Shur S. A. Negashev A. L. Subbotin D. V. Pelegov E. A. Borisova E. B. Blankova S. Trolier-McKinstry 《Physics of the Solid State》1999,41(2):274-277
The recrystallization kinetics of amorphous lead zirconate-titanate films prepared by sol-gel technology are investigated
experimentally using elastic scattering of light. Sequences of elastic dependences of the scattered light intensity are recorded
directly during thermal annealing. The evolution of the morphology of the film surface during annealing is described in terms
of the variation of their fractal dimensionalities D
s. The experimental dependences D
s(t) are compared with the results of a computer simulation of the phase transition kinetics in a thin plate (film).
Fiz. Tverd. Tela (St. Petersburg) 41, 306–309 (February 1999) 相似文献
6.
Using pulsed spectrometry with nanosecond time resolution, we have studied the characteristics of creation of induced defects
and the relaxation of such defects in the initial stage in ionic crystals, using as examples ten alkali halide crystals with
sc and fcc lattices and an MgF2 crystal in the temperature range 12.5–500 K. We present the transient absorption spectra, the relaxation kinetics for the
induced defects over a broad temperature range, the dependences of the creation and relaxation on the excitation flux density.
The results of our investigations are generalized in tables and, in the form of the most characteristic dependences, in figures.
We describe the model developed for evolution of primary defects, taking into account the main general characteristics observed
experimentally and the results of mathematical modeling based on it, which allowed us to put together a general picture for
the series of processes determining the evolution of primary defects.
Tomsk Polytechnical University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 5–29, November,
1996. 相似文献
7.
E. E. Gorodnichev A. I. Kuzovlev D. B. Rogozkin 《Journal of Experimental and Theoretical Physics》1999,88(3):421-432
Small-angle multiple scattering of circularly polarized waves in disordered systems composed of large (larger than the light
wavelength) spherical particles is discussed. The equation for Stokes’s fourth parameter V — the difference between the intensities of the left-and right-hand polarized light — is shown to have the form similar to
that of the scalar transport equation for intensity I, the only difference being the presence of an additional “non-small-angle” term responsible for depolarization. In the case
of small-angle scattering, depolarizing collisions are relatively rare and, in contrast to the scalar case, the problem contains
an additional spatial scale, namely the depolarization depth. The polarization degree and helicity of the scattered light
are calculated for the case of purely elastic scattering and in the presence of absorption in the medium. For strong absorption,
depolarization is shown to follow the transition to the asymptotic regime of wave propagation. The features appearing in strong
(non-Born) single scattering are also discussed.
Zh. éksp. Teor. Fiz. 115, 769–790 (March 1999) 相似文献
8.
A. A. Beznishchenko V. G. Makhan’kova N. A. Davidenko I. I. Davidenko V. N. Kokozei A. N. Popenaka 《Journal of Applied Spectroscopy》2007,74(4):533-536
We studied the effect of an electric field on the transmission of linearly polarized light through films of composites based
on polyvinylbutyral doped with particles of Cu(II)/Mn(II) complexes with “skeleton” and “planar” structures. The action of
an electrostatic field causes light absorption to become anisotropic. The effect increases with increasing distance between
the cation and anion. Its sign reverses if the spatial structure of the complex is changed. A phenomenological model is proposed
according to which the electrooptical properties of the composites are due to a change in the mutual orientation of complex
building blocks on exposure to an external electric field.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 481–484, July–August, 2007. 相似文献
9.
The effect of scattering of different multiplicity on polarization characteristics of scattered light is studied by the Monte Carlo computer simulation technique. The scattering multiplicity distribution versus the direction of scattering and dimensions of the scattering system is obtained for monodisperse systems of spherical particles of different size. The angular dependences of the elements of the light-scattering matrix (LSM) are calculated. It is shown that in a system of spherical particles, specific features of the LSM structure associated with multiple scattering have much in common with similar features of the LSM in systems of nonspherical particles under conditions of single scattering. The angular dependences of the degree of depolarization of the scattered light are studied. 相似文献
10.
L. P. Bulat I. A. Drabkin V. V. Karataev V. B. Osvenskii Yu. N. Parkhomenko D. A. Pshenai-Severin G. I. Pivovarov N. Yu. Tabachkova 《Physics of the Solid State》2011,53(1):29-34
The dependences of the electrical conductivity and thermopower on the size of grains in a nanocrystalline material based on
Bi2Te3-Sb2Te3 solid solutions of the p type have been investigated theoretically and experimentally. The relaxation time in the case of hole scattering by nanograin
boundaries in an isotropic polycrystal has been calculated taking into account the energy dependence of the probability of
tunneling of charge carriers and the dependence of the scattering intensity on the nanograin size L
n
. A decrease in the probability of boundary scattering with an increase in the energy of charge carriers leads to an increase
in the thermopower. The dependences of the thermopower and electrical conductivity on the nanograin size, which have been
obtained taking into account the boundary scattering and scattering by acoustic phonons, are in good agreement with experimental
data. For the material under consideration, the thermopower coefficient increases by 10–20% compared to the initial solid
solution at L
n
= 20–30 nm. This can lead to an increase in the thermoelectric figure of merit by 20–40%, provided that the decrease in the
electrical conductivity and the decrease in the lattice thermal conductivity compensate each other. Despite the absence of
a complete compensation, it has been possible to increase the thermoelectric figure of merit for the samples under investigation
to ZT = 1.10–1.12. 相似文献
11.
A study has been made of the slow relaxation of the dielectric permittivity of deuterated triglycine sulfate (DTGS) initiated
by application of a dc electric field. The field and temperature dependences of the relaxation time associated with domain-wall
motion were obtained. The effect of the internal electric field on relaxation processes is seen in different behavior of the
field and temperature dependences under different orientations of the external field. The existence in DTGS crystals of two
temperature regions of domain-structure rearrangement lying 7–8 and 15–18 °C below the Curie point has been established.
Fiz. Tverd. Tela (St. Petersburg) 40, 1542–1545 (August 1998) 相似文献
12.
G. Kh. Kitaeva P. S. Losevskii A. A. Mikhailovskii A. N. Penin 《Journal of Experimental and Theoretical Physics》1997,85(2):241-247
Four-wave Stokes k-spectra for light scattering on polaritons in lithium niobate crystals with an Mg impurity are studied experimentally. The
mechanisms for direct, cascade, coherent, and incoherent four-wave mixing of light are discussed in the course of interpreting
the angular dependences of the scattered light intensity. It is shown that the dispersion of the real part of the polariton
wave vector and the refractive index of the crystals at the polariton frequencies can be measured with an order of magnitude
greater accuracy than by spontaneous three-wave polariton light scattering. A significant discrepancy is found between determinations
of the polariton absorption coefficient from the angular spectra of three-wave scattering and four-wave scattering in terms
of the model employed here.
Zh. éksp. Teor. Fiz. 112, 441–452 (August 1997) 相似文献
13.
Based on the phenomenon of coherent spin Raman scattering a magnetooptical method of measuring the characteristics of the
reservoir of electronic spin-spin interactions in paramagnets was implemented. A formula relating the intensity of the inelastically
scattered light to the temperature of the spin-spin reservoirs under conditions of saturation of the EPR of paramagnetic ions
has been derived. For the Ce3+ ions in the (CexLa1−x)2Mg3(NO3)12·24H2O crystal values of the time of spin-lattice relaxation of the spin-spin reservoir and the local magnetic field have been
measured, and a relation between the spin-spin reservoir temperature and the external magnetic field strength under conditions
of stationary saturation of the EPR of the Ce3+ ions has been obtained.
V. I. Ul’yanov-Lenin Kazan State University,18, Lenin St., Kazan, 420008, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 76–81, January–February,
1997. 相似文献
14.
V. A. Loiko U. Maschke V. Ya. Zyryanov A. V. Konkolovich A. A. Miskevich 《Optics and Spectroscopy》2011,110(1):110-118
We considered light scattering by a polydisperse ensemble of droplets of a nematic liquid crystal. To model light scattering
by a monolayer of polymer-dispersed spherical droplets of a nematic liquid crystal with cylindrical symmetry of its internal
structure, we proposed a semianalytical modeling method. The method is based on interference approximation of the theory of
multiple wave scattering, anomalous diffraction approximation, and effective-medium approximation. The method takes into account
cooperative optical effects in concentrated, partially ordered layers and can be used to analyze the small-angle structure
of the intensity of scattered radiation in relation to the concentration, size, polydispersity of liquid crystal droplets,
orientation of their optical axes, and refractive indices of the liquid crystal and polymer. The obtained relations can be
applied to solving direct and inverse problems of light scattering in composite liquid crystal materials using data of polarization
measurements. We present graphical results of solving the direct problem for components of the polarization vector of scattered
wave. These results illustrate the formation of an angular structure for monolayers with a high concentration of polydisperse
droplets of the liquid crystal in the range of small scattering angles (0 < θ
s
≤ 8°). 相似文献
15.
The interrelation of depolarization and decorrelation of optical fields in multiply scattering Brownian media is studied on
the basis of the notion of the probability density of optical path lengths of the partial components of the scattered field
under multiple-scattering conditions. To describe such media a universal parameter that is independent of the density (concentration)
of scattering particles is introduced — the characteristic correlation time. Experimental results obtained with aqueous suspensions
of polystyrene beads as model media are presented which demonstrate the constancy of this parameter at different concentrations
of scattering particles.
Pis’ma Zh. éksp. Teor. Fiz. 67, No. 7, 455–460 (10 April 1998) 相似文献
16.
The volumetric integral equation formalism (VIEF) is used to determine characteristics of scattering of radiation falling
along the axis of dielectric cylinders that scatter the radiation. The spectral dependence of the extinction efficiency factor
Q is studied with changes in the length l of the cylinder (300–2200 nm), its width d (100–300 nm), and the refraction index
m (1.33–1.65). In the range of angles θ=0–180°, for a cylinder with l=700 nm, d=100 nm, and m=1.33, angular intensity distribution
functions ii and i2 are calculated for the components of the scattered radiation that are polarized perpendicular and parallel to the plane of
observation, respectively. No effect of scattered-radiation depolarization is found.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 2, pp. 256–260, March–April, 1998. 相似文献
17.
I. I. Shpak I. I. Rosola R. M. Evich S. I. Perechinski Yu. M. Vysochanski 《Journal of Applied Spectroscopy》2008,75(6):815-819
Raleigh and Mandelshtam-Brillouin light scattering has been investigated in chalcogenide glasses of the (As2S3)xI1−x system for x = 1.00−0.80. Longitudinal hypersound velocities, adiabatic elastooptical constants (p12)ad at frequencies of ∼15 GHz, and Landau-Placzek ratios RLP are found and scattering losses are calculated. Significant iodine additives are shown to result in the appearance of different
features in the behavior of concentration dependences of the investigated parameters.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 6, pp. 814–818, November–December, 2008. 相似文献
18.
V. V. Voitylov A. V. Voitylov E. N. Korytkova V. P. Romanov S. V. Ul’yanov V. V. Gusarov 《Optics and Spectroscopy》2009,106(1):50-55
Nanotubes suspended in a fluid medium have been investigated by the electrooptic method. This method is based on measuring the relative changes in the intensity of light transmitted through a suspension of nanotubes with application of an external electric field. The electrooptic effect (difference in these changes for transmitted light plane-polarized along the external field and perpendicularly to it) is analyzed. For aqueous suspensions of Mg3Si2O5(OH)4 nanotubes, the field and relaxation dependences of this effect are investigated. An analysis of the results obtained suggests that nanotubes, even when their concentration in water is low, form strong stable aggregates, which, however, can be elongated and enlarged under long-term action of strong rf fields. 相似文献
19.
V. I. Kadushkin 《Russian Physics Journal》2000,43(1):46-51
Characteristics of the Shubnikov-de Haas transverse magnetoresistance oscillations of 2D electrons in highly dopedAlGaAs(Si)/GaAs heterostructures are investigated in the present paper. Anomalies caused by the occupation of two quantization subbands are
revealed for samples with 2D-electron density ns>7·1011 cm−2 at T=1.7–16 K and magnetic field induction B up to 7.4 T. The dependences of the normalized oscillation amplitude on the
magnetic field show bends that typically displace toward weaker magnetic fields with decreasing temperature and electron density
ns. A nonmonotonic (oscillating) dependence of the Dingle temperature on the experimental temperature is found. These anomalies
are interpreted for a model of the occupation of two quantization subbands with electrons. They are caused by the competitive
character, of intersubband 2D-electron scattering. Small-angle relaxation times are estimated for 2D electrons of the zero
and first quantization subbands.
S. A. Esenin Ryazan' State Pedagogical University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1,
pp. 52–57, January, 2000. 相似文献
20.
A continuum approximation is used to find the magnetic component of absorption (its frequency, field, and orientation dependences)
related to the orientational relaxation of the localized magnetic moments of magnetic particles of a magnetic fluid dispersed
in a nonmagnetic fluid in the field of a plane stress wave.
Kursk State Technical University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 14–17, July,
1997. 相似文献