共查询到20条相似文献,搜索用时 31 毫秒
1.
V. I. Korepanov V. M. Lisitsyn V. I. Oleshko E. F. Polisadova S. S. Vil’chinskaya 《Journal of Applied Spectroscopy》2006,73(3):382-387
We have studied the spectral and kinetic characteristics of pulsed cathodoluminescence of feldspars (albite, microcline, amazonite)
in the time range 10−8–10−2 sec and the temperature range 28–300 K. We have shown that the bands in the UV region of the spectrum (5.39, 4.35, and 3.75
eV) are due to intrinsic luminescence of the crystals. The ratio of the intensities of these bands characterizes the phase
composition of the mineral: in the luminescence spectra of microcline, for all temperatures the 4.35 eV band dominates; in
the pulsed cathodoluminescence spectra of albite, the bands at 3.75 eV (at 300 K) and 5.39 eV (at 28 K) dominate. The parameters
of the luminescence decay kinetics for the impurity ions Fe3+ and Mn2+ are more sensitive to local perturbations of the lattice structure than the position of the emission band maximum, and can
be an effective indicator of the origin of the mineral.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 3, pp. 339–343, May–June, 2006. 相似文献
2.
M. M. Mikhailov 《Journal of Applied Spectroscopy》2006,73(1):79-84
The diffuse reflectance (DR) spectra and the cathodoluminescence (CL) spectra in the range 0.34–2.10 μm and changes in the
spectra after bombardment by accelerated electrons have been studied as a function of the specific surface area and the grain
sizes of titanium dioxide (rutile) powders of different grades (P1, P2, P02, R10). It has been established that the diffuse
reflection coefficient and the luminescence band intensity increase as the specific surface area decreases and the grain size
of the powder increases. A smaller specific surface area of the powders means lesser initial flareup and subsequent “quenching”
of the CL bands as a function of electron fluence. It has been shown that history-related differences between powders of different
grades is a less significant factor than the specific surface area in determining the diffuse reflectance and luminescence
and also the radiation resistance of the powders.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 73–77, January–February, 2006. 相似文献
3.
It has been found that on exposure of specimens of synthetic opal to UV radiation, luminescence is excited in them (337 nm)
that has spectral maxima at 400 and 500 nm. Its duration at half-height of a pulse is 9 nsec, and there is a weak slow component
with τ ∼ 1 μsec. The spectrum and intensity of the luminescence depend on the duration of irradiation and temperature. The
luminescence bands revealed relate to two individual luminescence centers, namely: the shortwave one, caused by the luminescence
centers formed in the bulk of the opal, and the longwave one, due to those formed on the opal surface.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 5, pp. 622–626, September–October, 2005. 相似文献
4.
We have studied the photoluminescence of calcite crystals. In the blue region of the photoluminescence spectrum of calcite
crystals obtained from Siberia (Russia) and from Saaremaa Island (Estonia), three strongly overlapping luminescence bands
due to intrinsic defects are observed. Luminescence due to impurities in the crystals are hardly detectable. The experimentally
measured time dependence of the luminescence intensity for the indicated luminescence bands is compared with the dependences
obtained as a result of a calculation based on a proposed model for the luminescence center. Better agreement between experiment
and calculation is achieved if the model of the luminescence center includes a metastable level with electron ejection energy
of 4 meV; the characteristic time for the radiative transition is 1.3 nsec. Studying the time dependence of the luminescence
at different wavelengths within the indicated bands allows us to conclude that the photoluminescence (three bands) is due
to one type of luminescence center.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 4, pp. 498–501, July–August, 2006. 相似文献
5.
Hrant Yeritsyan Vachagan Harutiunian Volodia Gevorkyan Norair Grigoryan Eleonora Hakhverdyan Sergey Nikoghosyan Aram Sahakyan Rudolf Gevorgyan Hakob Sargisyan Yeghis Keheyan 《Central European Journal of Physics》2005,3(4):623-635
Infrared (IR) absorption and luminescence in chemically and radiation-modified natural Armenian Zeolite (clinoptilolite) samples
have been studied. The luminescence was studied in 390–450 nm and 620–710 nm wavelength bands, and the IR measurements were
carried out in the 400–5400 cm−1 range. It is shown that the luminescence intensity depends on the content of pure clinoptilolite in the samples and, probably
on the distribution of “passive” luminescence centers over Si and Al sites that became “active” under radiation or chemical
treatment. The samples of electron irradiated clinoptilolite have higher luminescence intensity than the chemically and thermally
treated ones. A decrease in the intensity of IR absorption bands at 3550 cm−1 and 3650 cm−1 was found after irradiation. 相似文献
6.
Yu. V. Zorenko R. M. Turchak T. I. Voznyak A. P. Luchechko 《Journal of Applied Spectroscopy》2006,73(2):211-215
By liquid-phase epitaxy from an aqueous alcoholic solution, we have obtained films of the well-known storage phospor CsBr:Eu,
and we have studied their cathodoluminescence and photoluminescence (PL) spectra compared with the undoped CsBr films. We
have established that the structure of the photoluminescence centers of the CsBr:Eu films when excited by laser radiation
in the absorption band of the Eu2+ ions (λ = 337 nm) includes Eu2+-VCs isolated dipole centers and CsEuBr3 aggregate centers, and also luminescence centers based on inclusions of hydroxyl group OH− with the corresponding emission bands in the 440 nm, 520 nm, and 600 nm regions. We have studied the dependence of the spectra
and the intensity of the photoluminescence for CsBr:Eu films on annealing temperature in air at 423–483 K, compared with analogous
dependences for CsBr:Eu single crystals obtained from the melt. We have shown that annealing the films at T = 423–463 K leads
to rapid formation of CsEuBr3 aggregate luminescence centers, while for T > 473 K thermal degradation of these centers occurs.
We conclude that the observed differences between the photoluminescence spectra of CsBr:Eu films and CsBr:Eu single crystals
may be due to additional doping of the films with OH− ions.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 191–194, March–April, 2006. 相似文献
7.
E. M. Shishonok L. Trinkler S. V. Leonchik B. Berzinya 《Journal of Applied Spectroscopy》2008,75(4):567-575
Under high pressure and temperature conditions, we have obtained samples of thulium-activated cubic boron nitride in the form
of micropowders, ceramics, and polycrystals activated by thulium in the presence of aluminum. We studied the cathodoluminescence
(CL), photoluminescence (PL), and photoluminescence excitation spectra of the samples. In the luminescence spectra we observe
structured bands with maxima at ∼370, ∼475, ∼660, and ∼ 800 nm, assigned to electronic transitions in the triply charged thulium
ions. We have established that the most efficient method for excitation of “blue” luminescence at ∼475 nm for thulium ions
in cBN is excitation by an electron beam. The cBN samples synthesized in the presence of Al have photoluminescence spectra
with a more complex structure compared with samples not containing Al, with the band of dominant intensity at about 660 nm.
Hypothetically, this is a consequence of incorporation of thulium ions into the crystalline phases cBN and AlN, which are
equally likely to be formed during synthesis. The observed photoluminescence spectrum of the indicated samples is the superposition
of the photoluminescence spectra of the Tm3+ ions located in the crystal fields of cBN and AlN of different symmetries. The presence in the photoluminescence excitation
spectra (at 450, 490, and 660 nm) of structure, with features at wavelengths shorter than the excited photoluminescence, suggests
a nonresonant mechanism for its excitation. We have established that luminescence of Tm3+ ions is less intense than for other rare earth elements incorporated into cubic boron nitride.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 4, pp. 547–555, July–August, 2008. 相似文献
8.
We investigated thermally stimulated luminescence (TSL) of urine salts in the normal state and with oxalate, urate, and phosphate
salts. We found that the presence of pathological salts leads to a decrease of TSL intensity and to the appearance of additional
TLS bands with maxima at 118 and 205 K in addition to the characteristic bands at 173 and 260 K. The TLS bands are related
to the urine components. The TSL intensities of urine salts of different chemical composition are compared. The thermal activation
energy of the strongest TSL bands is determined.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 548–551, July–August, 2007. 相似文献
9.
N. K. Morozova I. A. Karetnikov V. V. Blinov V. K. Komar’ V. G. Galstyan D. P. Nalivaiko 《Journal of Applied Spectroscopy》2000,67(1):127-133
An investigation is made of the cathodoluminescence, electrical properties, and structural features of crystals of Cd1−xZnxTe solid solutions with composition x ranging from 0.02 to 0.20 mole fraction as compared with CdTe and ZnTe. The main bands
of the cathodoluminescence spectra are identified within the range 500–2700 nm. The role of oxygen in Cd1−xZnxTe cathodoluminescence is shown.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 1, pp. 96–100, January–February, 2000. 相似文献
10.
E. Kh. Baksht A. G. Burachenko V. I. Solomonov V. F. Tarasenko 《Russian Physics Journal》2011,54(6):634-638
Pulsed cathodoluminescence of spodumene and yttrium-aluminum garnet crystals activated by Mn2+ and Nd3+ ions, respectively, is investigated. The luminescence was excited upon crystal irradiation by electron beams with current
densities of 35 and 100 A/cm2 and average electron energy of ∼ 50 keV for 0.1, 0.25, and 0.65 ns. It is demonstrated that the electron beam duration decreased
to several tenth of a nanosecond does not lead to essential changes of the mechanisms of pulsed cathodoluminescence excitation
and character of its spectrum, but in this case, the intensity of luminescence of the hole centers increases compared with
the intracenter luminescence. 相似文献
11.
I. N. Ogorodnikov A. V. Kruzhalov E. A. Radzhabov L. I. Isaenko 《Physics of the Solid State》1999,41(2):197-201
A study of the luminescence characteristics of crystalline lithium triborate LiB3O5 (LBO) is reported. Investigation of the excitation and photoluminescence spectra of nominally pure, oriented LBO crystals
within broad spectral (1.2–10.5 eV) and temperature (8–500 K) regions, complemented by optical spectroscopy at the long-wavelength
fundamental-absorption edge, has revealed that the broad-band LBO luminescence in the 3.5–4.5-eV region is efficiently excited
by photons having energies above 7.5 eV in recombination processes and under corpuscular or x-ray irradiation. The totality
of the experimental data obtained permitted a conclusion that the LBO luminescence has an intrinsic nature and that it originates
from radiative decay of relaxed electronic excitations.
Fiz. Tverd. Tela (St. Petersburg) 41, 223–228 (February 1999) 相似文献
12.
M. M. Chugunova I. A. Kamenskikh V. V. Mikhailin S. A. Usenko 《Optics and Spectroscopy》2010,109(6):887-892
We present the results of studying the luminescence properties of transparent ceramics Y3Al5O12:Yb obtained by the vacuum sintering and nanocrystalline technology. In the course of research, we measured the luminescence
and luminescence excitation spectra, as well as the temperature and kinetic behavior of luminescence. Our results are analyzed
in comparison with the characteristics of corresponding single crystals. We revealed that processes of generation and relaxation
of electronic excitations that occur in ceramics, in particular, in the charge transfer state, are similar to processes occurring
in crystals. The behavior of two charge-transfer luminescence bands at 340 and 490 nm is studied. In the range 300–600 nm,
we revealed a broad emission band of radiation of other type, which is also observed in spectra of undoped ceramics. This
broad band is attributed to F+ centers. Emission and excitation spectra of charge transfer luminescence at a maximum of the temperature dependence of 100
K are measured for the first time. We found that, upon excitation in the charge transfer band, luminescence in ceramics is
more intense than in single crystals with similar concentrations of Yb and has a higher quenching temperature. 相似文献
13.
A. P. Voitovich A. N. Harbachova V. S. Kalinov A. P. Stupak 《Journal of Applied Spectroscopy》2008,75(6):791-797
Mathematical relations defining distortions from true values of photoluminescence intensities that arise during measurements
due to absorption at the luminescence frequencies are derived for various experimental designs. The adequacy of the derived
relations is confirmed by special experiments. The relations allow one to define correctly the contours, widths, and maximum
frequencies of luminescence bands of absorbing media and to deduce absorption coefficients of substances from luminescence
measurements.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 6, pp. 788–795, November–December, 2008. 相似文献
14.
B. Denker B. Galagan V. Osiko S. Sverchkov E. Dianov 《Applied physics. B, Lasers and optics》2007,87(1):135-137
A new Bi-doped boro-alumino-phosphate glass (BAP) composition was developed. Absorption and emission spectra and luminescence
decay kinetics were investigated. The emission spectrum consists of two wide bands in the visible (0.6–0.8 μm) and near-infrared
(∼1.0–1.5 μm) ranges. The luminescence decay curve investigation has revealed a complicated behavior dependent on both excitation
and registration wavelengths. In contrast to earlier investigated Bi-doped glasses, Bi:BAP has good technological properties
and can be easily scaled. This makes the developed glass composition interesting for broadband tunable (∼1.0–1.5 μm) lasers
and amplifiers.
PACS 32.70.Cs; 78.20.-e; 78.55.Qr 相似文献
15.
A. Ya. Khairullina T. V. Ol’shanskaya D. S. Filimonenko N. M. Kozlova Yu. M. Garmaza E. I. Slobozhanina 《Optics and Spectroscopy》2011,110(4):534-540
We studied changes in the surface of erythrocyte membranes exposed to the action of zinc sulfate in the concentration range
of 0.1–2.0 mM/l using methods of light scattering, spectrofluorimetry, and atomic force microscopy. Using the spectrofluorimetry
method, we revealed a dose-dependent increase in the fluorescence intensity of a fluorescamine probe incorporated into erythrocyte
membranes modified by zinc ions, which is indicative of an increase in the level of NH2 groups on the cell surface. Using atomic force microscopy, we revealed changes in the surface topography of erythrocyte membranes
exposed to the action of zinc sulfate in the concentration range of 0.1–2.0 mM/l. By performing a correlation analysis, we
revealed that the correlation length of the autocorrelation function of the erythrocyte surface irregularity profile directly
related to the fluorescence intensity of fluorescamine incorporated into erythrocyte membranes (r = 0.9, p < 0.05) modified by zinc ions. We showed that, in the zinc sulfate concentration range of 0.1–2.0 mM/l, zinc oxides form
in erythrocyte membranes, which is confirmed by the appearance of an absorption band at 330–340 nm and by an increase in the
light scattering. At more considerable concentrations, we identified absorption bands characteristic of zinc protein complexes
in erythrocyte membranes. A considerable decrease in the elongation of the scattering indicatrix of erythrocyte membranes
caused by luminescence correlates with the content of zinc proteins. Polarization measurements confirm the enhancement of
the aggregation of protein complexes observed by the atomic force microscopy method. The proposed complex approach can be
used in studies on the action of various abiotic factors on biological cells. 相似文献
16.
The properties of polycrystalline CdTe with a grain size of 5–30 μm have been investigated using the microphotoluminescence
methods of spectral analysis and topography. This material has been prepared by direct synthesis in a vapor flow of components
at a low temperature. The dominance of the Y and Z bands in the spectra reflects a nonequilibrium character of the crystallization processes. The superlinear dependences of
the luminescence intensity on the level of the band-to-band excitation indicate the exciton nature of the corresponding transitions.
The activation energies for temperature quenching of luminescence in the temperature range T = 100–150 K are found to be 120 meV for the Y luminescence and 180 meV for the Z luminescence, which correspond to the dissociation of excitons bound to defects with the transition of charge carriers to
the conduction and valence bands. The monochromatic topography data indicate that Y and Z defects have different material bases. 相似文献
17.
For an ensemble of different types of luminescence centers with overlapping absorption bands, with no restrictions on the
optical densities, we have obtained relations describing the luminescence excitation spectra for each type of center. We consider
transformations of the relations in some limiting cases. We suggest a procedure for using the equations obtained to determine
the characteristics of the luminescence centers. Some of these procedures have been experimentally implemented in study of
intrinsic radiation color centers in lithium fluoride crystals. We have determined the ratios of the luminescence quantum
yields for F2 and F3+ color centers, and we have observed that a major role is played by nonradiative transitions in deactivation of the first
excited singlet state of F3+ centers.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 3, pp. 365–371, May–June, 2008. 相似文献
18.
G. Remond 《Journal of luminescence》1977,15(2):121-155
Cathodoluminescence microscopy and cathodoluminescence spectrometry with the electron microprobe and the scanning electron microscope are applied to the study of some natural cassiterite, quartz and sphalerite crystals. Some examples of localization and distribution of crystalline defects revealed by cathodoluminescence microscopy are given. X-ray spectrometry and secondary ion mass analysis allow to illustrate the coincidence between the spatial variations of cathodoluminescence emission and the distribution of impurities within minerals. In order to establish a relationship between the spectral distribution of the luminescence and the nature of trace elements, comparisons are made between cathodoluminescence properties of natural and artificial zinc sulphide crystals. Particular attention is given to specimen containing copper-gallium impurities. It has been possible to distinguish between the impurities which can be responsible for the luminescence and those which are not associated with cathodoluminescence emission characteristic of the crystals. The study of cathodoluminescence intensity according to the excitation conditions led to consider the contribution of the X-ray photons generated in the specimen for the production of luminescence photons. An in-depth distribution law of generated photons similar to that used to take account of X-ray emission led to introduce an absorption function in the relation giving the measured intensity of cathodoluminescence according to the incident energy and the electron beam density. 相似文献
19.
We have measured the relative luminescence quantum yields and luminescence lifetimes of Tb(III) and Dy(III) ions in complexes
with pyrazole-5-carboxylic acids. Based on study of the time-resolved luminescence spectra of Tb(III) and Dy(III) complexes
with 3-(6-benzodioxanyl)pyrazole-5-carboxylic acid, we have demonstrated the possibility in principle of determining Dy(III)
in the presence of Tb(III) by separating the short-lived component of the luminescence of dysprosium, despite the practically
complete overlap of the analytical bands of dysprosium by the terbium bands. This method was used to determine Dy(III) in
luminescent materials: scandium borates doped with terbium and dysprosium.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 3, pp. 327–331, May–June, 2007. 相似文献
20.
For the first time, we have assigned the observed absorption bands and interpreted the IR spectrum of methyl-β-D-glucopyranoside
in detail in the 1500–800 cm−1 region, based on a full calculation of the frequencies and absolute intensities of the normal vibrations of the molecule
and their comparison with the experimental data. We have identified two groups of spectral signs indicating an oxymethyl substituent
has replaced the hydroxyl group on the C(1) atom in the glucopyranoside: absorption bands of medium intensity due to the characteristic vibrations of the substituent,
and intense bands due to an unusual “interaction” between many structural moieties.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 721–727, November–December, 2006. 相似文献