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1.


    Aplesnin, S. S.
    Magnetic capacitance in variable-valence manganese sulfides / S. S. Aplesnin, A. M. Kharkov, G. Y. Filipson // Phys. Status Solidi B. - 2020. - Vol. 257, Is. 5. - Ст. 1900637, DOI 10.1002/pssb.201900637. - Cited References: 12. - This study was supported by the Russian Foundation for Basic Research No. 18-32-00079 mol_a. The reported study was funded by Russian Foundation for Basic Research, Government of Krasnoyarsk Territory, Krasnoyarsk Regional Fund of Science No. 18-42-240001 r_a . - ISSN 0370-1972
Кл.слова (ненормированные):
Debye model -- infrared spectroscopy -- magnetocapacitance -- permittivity -- relaxation time
Аннотация: The permittivity of TmxMn1–xS (0 < x < 0.15) solid solutions is measured in the frequency range of 102–106 Hz at temperatures of 300–500 K in magnetic fields of up to 12 kOe. The migration and relaxation conductivity contributions to the electric polarization are established. The relaxation time and activation energy are calculated using the Debye model. A decrease in the capacitance and relaxation time in a magnetic field is observed. The electron polarization relaxation channel provided by recombination of the electron–hole pairs is found using the infrared spectroscopy investigations.

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Держатели документа:
Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Akademgorodok 50 bld. 38, Krasnoyarsk, 660036, Russian Federation
Institute of Space Technology, Reshetnev Siberian State University of Science and Technology, Krasnoyarskiy rabochiy Ave., 31, Krasnoyarsk, 660037, Russian Federation

Доп.точки доступа:
Kharkov, A. M.; Filipson, G. Y.; Аплеснин, Сергей Степанович
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2.


    Averyanov, E. M.
    New features in the structural relaxation of a nematic liquid-crystal doped with luminescent impurity molecules / E. M. Averyanov, V. A. Gunyakov // JETP Letters. - 1993. - Vol. 57, Is. 8. - P. 492-496. - Cited References: 15 . - ISSN 0021-3640
РУБ Physics, Multidisciplinary
Рубрики:
FLUORESCENCE DEPOLARIZATION
   ORIENTATIONAL RELAXATION

   FLUOROPHORES

Аннотация: A new approach is proposed for interpreting the polarized fluorescence spectra of an impure liquid crystal in which the orientational order of excited impurity molecules has undergone relaxation. This approach has also been realized experimentally. The new experimental data demonstrate a new relaxation process with a time scale on the order of 10(-11)-10(-9) s.

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Доп.точки доступа:
Gunyakov, V. A.; Гуняков, Владимир Алексеевич; Аверьянов, Евгений МихайловичAver'yanov
}
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3.


    AVERYANOV, E. M.
    POLARIZED LUMINESCENCE SPECTRUM OF IMPURITY LIQUID-CRYSTAL - THE DEGENERATION LIFTED AND RENEWED BY RELAXATION / E. M. AVERYANOV // Zhurnal Eksperimentalnoi Teor. Fiz. - 1993. - Vol. 103, Is. 6. - P. 2018-2038. - Cited References: 45 . - ISSN 0044-4510
РУБ Physics, Multidisciplinary
Рубрики:
RESOLVED FLUORESCENCE DEPOLARIZATION
   UNIAXIAL MOLECULAR SAMPLES

   NEMATIC ORDER PARAMETERS

   EXCITED-STATES

   SPECTROSCOPY

   MEMBRANES

   FLUOROPHORES

   ORIENTATION

   TRANSITION

   DYES

Аннотация: The general molecular-statistical approach is proposed for the analysis or the polarized luminescence spectrum for impurity molecule of an arbitrary symmetry in the nematic liquid crystal matrix. On the particular example of uniaxial molecules the influence of features of the molecular electron structure, orientational statistics, molecular dynamics, and features of the anisotropic intermolecular coupling upon the positions of maxima v(if)(t) of impurity fluorescence polarized bands J(ij)(t) is studied. For the first time it is shown that all these factors significantly affect the degree of spectrum v(ij)(t) degeneration. For t not-equal 0, relaxation of excited impurity molecule subsystem toward the orientational distribution lifts a partial degeneration of spectrum v(ij), occuring at t not-equal 0, and renews partial or total degeneration of spectrum v(ij) in the limit t = infinity. In the lack of the spectrum v(ij) degeneration for t = 0 the relaxation may restore partial degeneration for t not-equal 0 as a function of the features of electron structure of molecules. The results of work explain the familiar experimental data on the number of independent component v(ij) and relation between them, on dependence of v(ij) upon the order of matrix and impurity subsystem, on the mutual relation in the positions of impurity band polarized component in the absorption and fluorescence spectra.

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4.


    Averyanov, E. M.
    Splitting of polarized impurity fluorescence bands in the steady-state spectrum of an isotropic solution / E. M. Averyanov // JETP Letters. - 1994. - Vol. 59, Is. 1. - P. 23-26. - Cited References: 12 . - ISSN 0021-3640
РУБ Physics, Multidisciplinary
Рубрики:
RELAXATION
Аннотация: A difference is predicted between the peaks, nu(VV) and nu(VH), Of the polarized components J(VV)(nu) and J(VH)(nu) in the steady-state spectrum of impurity fluorescence in an isotropic solution. This difference would result from a temporal correlation between an orientational Brownian diffusion of excited fluorescing molecules and a structural relaxation of the surrounding matrix molecules.

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Доп.точки доступа:
Аверьянов, Евгений МихайловичAver'yanov
}
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5.


    Belyaev, B. A.
    Dielectric relaxation of trans-4-propyl-(4-cyanophenyl)-cyclohexane liquid crystals / B. A. Belyaev, N. A. Drokin, V. F. Shabanov // Phys. Solid State. - 2004. - Vol. 46, Is. 3. - P. 579-583, DOI 10.1134/1.1687882. - Cited References: 11 . - ISSN 1063-7834
Аннотация: The frequency dependences of the permittivity of a trans-4-propyl-(4-cyanophenyl)-cyclohexane (3PCH) liquid crystal in the nematic phase are measured in the frequency range 1-2000 MHz for different orientations of the director of liquid-crystal molecules with respect to the polarization of an ac electric field. The temperature dependences of the dielectric and optical characteristics are compared in the range of the transition from the nematic phase to the isotropic liquid phase. The dielectric spectra are approximated numerically, and the times of dipole relaxation upon rotation of the molecules about the short and long axes are determined. It is demonstrated that intramolecular motions make a significant contribution to the relaxation. The activation enthalpies are calculated. (C) 2004 MAIK "Nauka / Interperiodica".

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Публикация на русском языке Беляев, Борис Афанасьевич. Диэлектрическая релаксация жидкого кристалла транс-4-пропил(4-цианфенил) циклогексан [Текст] / Б. А. Беляев, Н. А. Дрокин, В. Ф. Шабанов // Физ. тверд. тела. - 2004. - Т. 46 Вып. 3. - С. 559-562

Держатели документа:
Russian Acad Sci, LV Kirensky Phys Inst, Siberian Div, Krasnoyarsk 660036, Russia

Доп.точки доступа:
Drokin, N. A.; Дрокин, Николай Александрович; Shabanov, V. F.; Шабанов, Василий Филиппович; Беляев, Борис Афанасьевич
}
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6.


    Belyaev, B. A.
    Distribution function of relaxation times for a 4-n-pentyl-4 '-cyanobiphenyl liquid crystal / B. A. Belyaev, N. A. Drokin, V. F. Shabanov // Phys. Solid State. - 2005. - Vol. 47, Is. 9. - P. 1791-1796, DOI 10.1134/1.2045369. - Cited References: 15 . - ISSN 1063-7834
РУБ Physics, Condensed Matter
Рубрики:
DIELECTRIC-RELAXATION
   SPECTRA

   INVERSION

Аннотация: The distribution function of relaxation times is reconstructed from the dielectric loss spectrum measured over a wide range of frequencies for a 4-n-pentyl-4'-cyanobiphenyl (5CB) liquid crystal. It is demonstrated that the distribution function for the isotropic and nematic phases is asymmetric in shape. Comparison shows that the reconstructed distribution function is in qualitative agreement with similar functions that are analytically derived from the Cole-Davidson and Havriliak-Negami empirical equations. The specific features observed in the behavior of the distribution function with a variation in the angle between the direction of polarization of a microwave electric field and the director of the liquid-crystal molecules are analyzed. A complex dependence of the permittivity for the liquid crystal in the range of ultrahigh frequencies is explained in terms of additional relaxation mechanisms associated with different motions of molecular fragments of alkyl chains. (c) 2005 Pleiades Publishing, Inc.

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Держатели документа:
Russian Acad Sci, LV Kirensky Phys Inst, Siberian Div, Krasnoyarsk 660036, Russia
ИФ СО РАН
Kirensky Institute of Physics, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk, 660036, Russian Federation

Доп.точки доступа:
Drokin, N. A.; Дрокин, Николай Александрович; Shabanov, V. F.; Шабанов, Василий Филиппович; Беляев, Борис Афанасьевич
}
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7.


    Belyaev, B. A.
    Impedance spectroscopy study of the electrical properties of cation-substituted barium hexaaluminate ceramics / B. A. Belyaev, N. A. Drokin, V. A. Poluboyarov // Phys. Solid State. - 2018. - Vol. 60, Is. 2. - P. 274-280, DOI 10.1134/S1063783418020063. - Cited References:18 . - ISSN 1063-7834. - ISSN 1090-6460
РУБ Physics, Condensed Matter
Рубрики:
DIELECTRIC-RELAXATION
   LIQUID-CRYSTALS

   SPECTRA

Аннотация: We report on the behavior of frequency and temperature dependences of the impedance of a measuring cell in the form of a parallel-plate capacitor filled with barium hexaaluminate ceramics with four aluminum cations replaced by iron (BaO · 2Fe2O3 · 4Al2O3). The measurements have been performed in the frequency range of 0.5–108 Hz at temperatures of 20-375°C. A technique for determining the electrical properties of the investigated ceramics is proposed, which is based on an equivalent electric circuit allowing the recorded impedance spectra to be approximated with sufficiently high accuracy. The established spectral features are indicative of the presence of two electric relaxation times different from each other by three orders of magnitude. This fact is explained by the difference between the charge transport processes in the bulk of crystallites and thin intercrystallite spacers, for which the charge activation energies have been determined.

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Публикация на русском языке Беляев, Борис Афанасьевич. Исследование электрофизических характеристик катион-замещенной керамики гексаалюмината бария методом импедансной спектроскопии [Текст] / Б. А. Беляев, Н. А. Дрокин, В. А. Полубояров // Физ. тверд. тела. - 2018. - Т. 60 Вып. 2. - С. 269–275

Держатели документа:
Russian Acad Sci, Kirensky Inst Phys, Fed Res Ctr KSC SB RAS, Krasnoyarsk 660036, Russia.
Siberian Fed Univ, Krasnoyarsk 660041, Russia.
Siberian State Aerosp Univ, Krasnoyarsk 660014, Russia.
Russian Acad Sci, Inst Solid State Chem & Mechanochem, Siberian Branch, Krasnoyarsk 660036, Russia.

Доп.точки доступа:
Drokin, N. A.; Дрокин, Николай Александрович; Poluboyarov, V. A.; Беляев, Борис Афанасьевич
}
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8.


    Belyaev, B. A.
    Reconstruction of the distribution function of relaxation times for 7CB and 7OCB liquid crystals from dielectric spectra / B. A. Belyaev, N. A. Drokin, V. F. Shabanov // Phys. Solid State. - 2006. - Vol. 48, Is. 5. - P. 973-978, DOI 10.1134/S106378340605026X. - Cited References: 16 . - ISSN 1063-7834
РУБ Physics, Condensed Matter
Рубрики:
DECIMETER WAVELENGTH RANGE
   FEATURES

Аннотация: A technique for reconstructing the distribution function of relaxation times from the dielectric spectra measured over a wide range of frequencies is proposed and tested using 7CB and 7OCB liquid crystals as examples. The objective function, which is the sum of the squares of the differences between the calculated and measured permittivities, is minimized with the Mathcad program package. It is demonstrated that, in the case of parallel orientation of the molecular director with respect to the polarization of the ac electric field, the distribution function of relaxation times is consistent with the Debye relaxation model; however, there are insignificant deviations in the short-time interval corresponding to the high-frequency portion of the dielectric spectrum. For perpendicular orientation of the director, the distribution function of relaxation times exhibits specific features that are most pronounced for the 7OCB liquid crystal and probably reflect intramolecular motions of the rigid core and fragments of the alkyl chain.

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Держатели документа:
Russian Acad Sci, Siberian Div, LV Kirensky Phys Inst, Krasnoyarsk 660036, Russia
ИФ СО РАН
Kirensky Institute of Physics, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk, 660036, Russian Federation

Доп.точки доступа:
Drokin, N. A.; Дрокин, Николай Александрович; Shabanov, V. F.; Шабанов, Василий Филиппович; Беляев, Борис Афанасьевич
}
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9.


    Belyaev, B. A.
    Temperature dependence of the dielectric characteristics of a 5CB liquid crystal within the relaxation region / B. A. Belyaev, N. A. Drokin, V. F. Shabanov // Phys. Solid State. - 2005. - Vol. 47, Is. 4. - P. 765-768, DOI 10.1134/1.1913994. - Cited References: 9 . - ISSN 1063-7834
РУБ Physics, Condensed Matter
Рубрики:
SERIES
Аннотация: The temperature dependence of the real part of the permittivity of a 4-n-pentyl-4-cyanobiphenyl liquid crystal was studied within a broad frequency range of 30-5000 MHz and in the temperature interval 20-60 degrees C in the vicinity of the nematic-isotropic-liquid phase transition. It was established that the dispersion of the longitudinal component of the permittivity can be fitted well by a sum of two Debye terms with strongly differing relaxation times. The temperature and frequency dependence of the shorter relaxation time was determined for which the best fit between calculations and experiment was achieved. (C) 2005 Pleiades Publishing, Inc.

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Держатели документа:
Russian Acad Sci, Siberian Div, LV Kirensky Phys Inst, Krasnoyarsk 660036, Russia
ИФ СО РАН
Kirensky Institute of Physics, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk, 660036, Russian Federation

Доп.точки доступа:
Drokin, N. A.; Дрокин, Николай Александрович; Shabanov, V. F.; Шабанов, Василий Филиппович; Беляев, Борис Афанасьевич
}
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10.


    Berman, G. P.
    A quantum nonlinear resonance with account of relaxation processes / G. P. Berman, A. R. Kolovsky // Physica A. - 1987. - Vol. 141, Is. 2-3. - P. 602-612, DOI 10.1016/0378-4371(87)90186-5. - Cited References: 12 . - ISSN 0378-4371
РУБ Physics, Multidisciplinary


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Доп.точки доступа:
Kolovsky, A. R.; Коловский, Андрей Радиевич; Берман, Геннадий Петрович
}
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11.


    Berzhanskii, V. N.
    Ccritical relaxation in CDCR2SE4 ferromagnet / V. N. Berzhanskii, V. I. Ivanov // Fiz. Tverd. Tela. - 1980. - Vol. 22, Is. 6. - P. 1871-1873. - Cited References: 7 . - ISSN 0367-3294
РУБ Physics, Condensed Matter


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Доп.точки доступа:
Ivanov, V. I.; Бержанский, Владимир Наумович
}
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12.


    Berzhanskii, V. N.
    Critical relaxation of uniform precession of magnetization in cubic ferrimagnets / V. N. Berzhanskii, V. I. Ivanov // Phys. Status Solidi B. - 1989. - Vol. 151, Is. 1. - P. 259-267, DOI 10.1002/pssb.2221510130. - Cited References: 22 . - ISSN 0370-1972
РУБ Physics, Condensed Matter


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Держатели документа:
LV KIRENSKII PHYS INST,KRASNOYARSK 660036,USSR
ИФ СО РАН
Доп.точки доступа:
Ivanov, V. I.; Бержанский, Владимир Наумович
}
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13.


    Berzhanskii, V. N.
    Electron-paramagnetic-res relaxation in chromium chalcogenide spinels / V. N. Berzhanskii, S. A. GAVRICHKOV, V. I. IVANOV // Fiz. Tverd. Tela. - 1982. - Vol. 24, Is. 7. - P. 2215-2218. - Cited References: 8 . - ISSN 0367-3294
РУБ Physics, Condensed Matter


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Доп.точки доступа:
GAVRICHKOV, S. A.; IVANOV, V. I.; Бержанский, Владимир Наумович
}
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14.


    Berzhanskii, V. N.
    Relaxation of uniform magnetization precession in collinear cubic ferrimagnets in the paramagnetic neighborhood of TC / V. N. Berzhanskii, V. I. Ivanov, A. V. Lazuta // JETP Letters. - 1990. - Vol. 52, Is. 9. - P. 483-487. - Cited References: 10 . - ISSN 0021-3640
РУБ Physics, Multidisciplinary
Рубрики:
CDCR2SE4
Аннотация: The characteristic features of the critical spin dynamics of the cubic ferrimagnets Y3Fe5O12 and MnFe2O4 in the exchange temperature region above T(c) have been studied. The magnetic-dipole relaxation of the uniform magnetization of these ferrimagnets is shown to be suppressed. The relaxation channel due to the local uniaxial anisotropy, with a new temperature dependence, is the dominant channel.

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Держатели документа:
LV KIRENSKY PHYS INST,KRASNOYARSK,USSR
ИФ СО РАН

Доп.точки доступа:
Ivanov, V. I.; Lazuta, A. V.; Бержанский, Владимир Наумович
}
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15.


    Berzhanskii, V. N.
    Spin-phonon relaxation processes in CDCR2SE4 crystals / V. N. Berzhanskii, V. I. Ivanov // Fiz. Tverd. Tela. - 1980. - Vol. 22, Is. 4. - P. 1233-1235. - Cited References: 10 . - ISSN 0367-3294
РУБ Physics, Condensed Matter


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Доп.точки доступа:
Ivanov, V. I.; Бержанский, Владимир Наумович
}
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16.


    Bobrov, P. P.
    Dielectric permittivity spectra of oil-water-saturated sandy-clayey rocks of different mineralogical compositions and relaxation properties of water in these rocks / P. P. Bobrov, V. L. Mironov, A. V. Repin // Russ. Geol. Geophys. - 2015. - Vol. 56, Is. 7. - P. 1065-1073, DOI 10.1016/j.rgg.2015.06.007. - Cited References: 21. - This work was supported by RFBR (grant nos. 12-05-00502a and 14-05-00151a). . - ISSN 1068-7971
РУБ Geosciences, Multidisciplinary
Рубрики:
MOIST SOILS
   FREQUENCY

   MODEL

   TEMPERATURE

   SALINITY

   RANGE

   GHZ

Кл.слова (ненормированные):
Conductivity -- Dielectric permittivity -- Multifrequency dielectric relaxation -- Oil-bearing deposits -- Sandy-clayey rocks
Аннотация: Experimental measurements of the dielectric permittivity and equivalent conductivity of sandy-clayey samples (a mixture of river sand with bentonite or kaolin) saturated with salt-solution-diesel-fuel emulsions were performed in the frequency range from 10 kHz to 1 GHz at temperatures of 25-65 °C. It is shown that when the content of the salt solution in the saturating fluid does not exceed 10%, the dielectric permittivity in the frequency range from 1 MHz to 1 GHz depends little on the mineral composition of the sample and on the concentration of the saturating solution. When the portion of water is 33.3% or higher, increasing the concentration of the salt solution leads to an increase in the equivalent conductivity and the real part of the complex dielectric permittivity. Using the refractive model of the complex dielectric permittivity, we have estimated the dielectric properties of bound water, which depend on temperature and the type of clay (bentonite or kaolin) in the sand-clay mixture but are independent of the water saturation and the amount of clay in the sample.

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Публикация на русском языке Бобров, Павел Петрович. Спектры диэлектрической проницаемости нефтеводонасыщенных песчано-глинистых пород различного минералогического состава и релаксационные свойства воды в этих породах [Текст] / П. П. Бобров, В. Л. Миронов, А. В. Репин // Геол. и геофиз. - Новосибирск : Изд-во СО РАН, 2015. - Т. 56 № 7. - С. 1359-1368

Держатели документа:
Omsk State Pedagogical University, Naberezhnaya im. Tukhachevskogo 14, Omsk, Russian Federation
L.V. Kirenskii Institute of Physics, Siberian Branch of the Russian Academy of Sciences, Akademgorodok 50, str. 38, Krasnoyarsk, Russian Federation
M.F. Reshetnev Siberian State Aerospace University, pr. im. Gazety Krasnoyarskii Rabochii 31, Krasnoyarsk, Russian Federation

Доп.точки доступа:
Mironov, V. L.; Миронов, Валерий Леонидович; Repin, A. V.; RFBR [12-05-00502a, 14-05-00151a]
}
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17.


    Bobrov, P. P.
    The effect of dielectric relaxation processes on the complex dielectric permittivity of soils at frequencies from 10 kHz to 8 GHz—Part II: Broadband analysis / P. P. Bobrov, E. S. Kroshka, K. V. Muzalevskiy // IEEE Trans. Geosci. Remote Sens. - 2024. - Vol. 62. - Ст. 2000411, DOI 10.1109/TGRS.2023.3340693. - Cited References: 51 . - ISSN 0196-2892. - ISSN 1558-0644
   Перевод заглавия: Эффект процессов диэлектрической релаксации на комплексную диэлектрическую проницаемость почв на частотах от 10 кГц до 8 ГГц
Кл.слова (ненормированные):
dielectric measurement -- Dobson dielectric model -- Maxwell–Wagner effect -- refraction-relaxation model -- soil moisture
Аннотация: This article is the second in a series evaluating the effect of dielectric relaxation processes on the relatively effective complex dielectric permittivity (RCP) of soils. Part II is based on the results of experimental measurements in the frequency range 10 kHz to 8–20 GHz. The broadband dielectric spectrum model includes the high-frequency part as a model of the dielectric mixture and the relaxation part as the sum of three relaxation processes modeled by the Debye and Cole–Cole formulas. For modeling the high-frequency part of the spectrum, the Dobson and Mironov models were considered as possible options. As stated in Part I, the influence of relaxation processes on the imaginary part of the RCP extends up to frequencies of units of gigahertz. The increase in the imaginary part in these models was compensated by unrealistically high values of the specific electrical conductivity of free and bound water. We examined the correspondence of these models to experimental data at frequencies above 2–5 GHz, assuming that the conductivity of bound and free water is zero. The parameters of relaxation processes were found while solving the least-square optimization problem using the technique for determining the continuous distribution of relaxation times (DRTs). Found process parameters depend on the content of clay, organic carbon, and moisture of the samples. The more clay is in the soil, the greater the strength of these processes is. The influence of organic carbon with the conditions being equal consists in the reduction of the real and imaginary parts of RCP.

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Держатели документа:
Faculty of Physics, Omsk State Pedagogical University, 644043 Omsk, Russia
Omsk Scientific Center SB RAS (Institute of Radiophysics and Physical Electronics), 644099 Omsk, Russia
Kirensky Institute of Physics Federal Research Center KSC Siberian Branch Russian Academy of Sciences, 660036 Krasnoyarsk, Russia

Доп.точки доступа:
Kroshka, E. S.; Muzalevskiy, K. V.; Музалевский, Константин Викторович
}
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18.


   
    Cluster embedding in an elastic polarizable environment: Density functional study of Pd atoms adsorbed at oxygen vacancies of MgO(001) / V. A. Nasluzov [et al.] // J. Chem. Phys. - 2001. - Vol. 115, Is. 17. - P. 8157-8171, DOI 10.1063/1.1407001. - Cited References: 88 . - ISSN 0021-9606
РУБ Physics, Atomic, Molecular & Chemical
Рубрики:
TRANSITION-METAL ATOMS
   AB-INITIO

   OXIDE SURFACES

   ELECTRONIC-PROPERTIES

   ENERGY CALCULATIONS

   MOLECULAR-DYNAMICS

   MOTT-LITTLETON

   MADELUNG FIELD

   IONIC-CRYSTAL

   MGO

Кл.слова (ненормированные):
Atoms -- Binding energy -- Computer simulation -- Electron energy levels -- Electronic structure -- Magnesia -- Oxygen -- Palladium -- Polarization -- Probability density function -- Quantum theory -- Relaxation processes -- Charged defects -- Cluster embedding -- Elastic polarizable environment -- Electron affinity -- Oxygen vacancies -- Adsorption
Аннотация: Adsorption complexes of palladium atoms on F-s, F-s(+), F-s(2+), and O2- centers of MgO(001) surface have been investigated with a gradient-corrected (Becke-Perdew) density functional method applied to embedded cluster models. This study presents the first application of a self-consistent hybrid quantum mechanical/molecular mechanical embedding approach where the defect-induced distortions are treated variationally and the environment is allowed to react on perturbations of a reference configuration describing the regular surface. The cluster models are embedded in an elastic polarizable environment which is described at the atomistic level using a shell model treatment of ionic polarizabilities. The frontier region that separates the quantum mechanical cluster and the classical environment is represented by pseudopotential centers without basis functions. Accounting in this way for the relaxation of the electronic structure of the adsorption complex results in energy corrections of 1.9 and 5.3 eV for electron affinities of the charged defects F-s(+) and F-s(2+), respectively, as compared to models with a bulk-terminated geometry. The relaxation increases the stability of the adsorption complex Pd/F-s by 0.4 eV and decreases the stability of the complex Pd/F-s(2+) by 1.0 eV, but it only weakly affects the binding energy of Pd/F-s(+). The calculations provide no indication that the metal species is oxidized, not even for the most electron deficient complex Pd/F-s(2+). The binding energy of the complex Pd/O2- is calculated at -1.4 eV, that of the complex Pd/F-s(2+) at -1.3 eV. The complexes Pd/F-s and Pd/F-s(+) exhibit notably higher binding energies, -2.5 and -4.0 eV, respectively; in these complexes, a covalent polar adsorption bond is formed, accompanied by donation of electronic density to the Pd 5s orbital. (C) 2001 American Institute of Physics.

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Держатели документа:
Russian Acad Sci, Inst Chem & Chem Technol, Krasnoyarsk 660049, Russia
Tech Univ Munich, Inst Phys & Theoret Chem, D-85747 Garching, Germany
Kemerovo State Univ, Dept Phys, Kemerovo 650043, Russia
ИХХТ СО РАН
Institute of Chemistry and Chemical Technology, Russian Academy of Sciences, 660049 Krasnoyarsk, Russian Federation
Institut fur Physikalische und Theoretische Chemie, Technische Universitat Munchen, 85747 Garching, Germany

Доп.точки доступа:
Nasluzov, V. A.; Rivanenkov, V. V.; Gordienko, A. B.; Neyman, K. M.; Birkenheuer, U.; Rosch, N.
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19.


   
    Dielectric properties of a mixed-valence Pb3Mn7O15 manganese oxide / N. V. Volkov [et al.] // J. Phys.: Condens. Matter. - 2010. - Vol. 22, Is. 37. - Ст. 375901, DOI 10.1088/0953-8984/22/37/375901. - Cited References: 14. - This study was supported by the Russian Foundation for Basic Research 'Siberia', project No. 09-02-98003, and the Siberian Branch of the Russian Academy of Sciences, integration project No. 101. . - ISSN 0953-8984
РУБ Physics, Condensed Matter

Кл.слова (ненормированные):
cation -- lead -- manganese derivative -- oxide -- article -- chemical model -- chemistry -- crystallization -- electric conductivity -- electronics -- methodology -- temperature -- Cations -- Crystallization -- Electric Conductivity -- Electronics -- Lead -- Manganese Compounds -- Models, Chemical -- Oxides -- Temperature -- AC electric field -- Analysis of resistivity -- Carrier hopping -- Charge ordering -- Complex dielectric constant -- Crystal site -- Debye models -- Dielectric constants -- Dielectric spectra -- Frequency windows -- Lattice sites -- Low frequency -- Manganese ions -- Mixed valence -- Mixed valence state -- Relaxation behaviors -- Temperature range -- Electric fields -- Manganese -- Manganese oxide -- Permittivity -- Single crystals -- Crystal symmetry
Аннотация: We investigated the low-frequency dielectric properties of a Pb3Mn7O15 single crystal with manganese ions in the mixed-valence state (Mn3+/Mn4+). Dielectric relaxation was found in the frequency window from 20 to 100 kHz in the temperature range 110-180 K. The dielectric spectra of the crystal were analyzed using a Debye model. Estimations made within the model and analysis of resistivity data suggest that the relaxation behavior of the dielectric constant is related to polaronic charge carrier hopping. Around 250 K, charge ordering occurs in the crystal when the Mn3+ and Mn4+ ions are arranged in a specific order among the crystal sites. With a decrease in temperature, an ac electric field can induce a charge hop between the equivalent lattice sites available, related to crystal symmetry. This hopping is equivalent to the reorientation of an electric dipole that yields Debye-type behavior of the complex dielectric constant. The observed anisotropy in the behavior of the dielectric properties and resistivity can be attributed to a pronounced two-dimensional character of the crystal structure.

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Держатели документа:
[Volkov, N. V.
Eremin, E. V.
Sablina, K. A.
Sapronova, N. V.] Russian Acad Sci, LV Kirensky Phys Inst, Siberian Branch, Krasnoyarsk 660036, Russia
ИФ СО РАН
L V Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk, Russia.
L V Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk 660036, Russian Federation

Доп.точки доступа:
Volkov, N. V.; Волков, Никита Валентинович; Eremin, E. V.; Еремин, Евгений Владимирович; Sablina, K. A.; Саблина, Клара Александровна; Sapronova, N. V.
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20.


   
    Dielectric relaxation and phase transition behavior of (1–x)Pb(Zn1/3Nb2/3)O3-xBaTiO3 binary solid solutions / Q. Gao [et al.] // Ceram. Int. - 2018. - Vol. 44, Is. 15. - P. 18491-18498, DOI 10.1016/j.ceramint.2018.07.069. - Cited References: 53. - This work was supported by the National Basic Research Program of China (Grant No. 2015CB654602 ), the International Science & Technology Cooperation Program of China (Grant No. 2015DFA51100 ), the NSFC projects (Grant Nos. 51761145024 and 51772239 ), Shaanxi province project 2017 ktpt-21, the Joint fund of the Ministry of Education (Grant No. 6141A02033210 ) and the 111 Project under Grant No. B14040 . The SEM work was done at International Center for Dielectric Research (ICDR), Xi’an Jiaotong University, Xi’an, China. . - ISSN 0272-8842
Кл.слова (ненормированные):
Dielectric relaxation -- Phase transition -- “U”-shaped variation -- Polarization mismatch
Аннотация: Dielectric relaxation and phase transition behaviors in (1–x)Pb(Zn1/3Nb2/3)O3-xBaTiO3 (PZN-BT) binary solid solutions have been systematically studied in this paper. All the compositions display a pure pseudo-cubic perovskite structure. As the BT contents increase from 10 mol% to 70 mol%, the phase transition peak becomes broader and broader, accompanying with decreases of ɛm (the maximum dielectric permittivity) and Tm (the temperature corresponds to the ɛm). Nevertheless, an abnormal increase of ɛm and Tm occurs when the BT contents exceeds 70 mol%, forming a “U” shaped curve of the compositional dependence of ɛm and Tm. Moreover, it is indicated from the new glass model fitting results that the characteristic parameter p, which represents the degree of relaxation, also shows a similar “U” shaped variation curve. Similarly, as shown in polarization-electric field loops, both remnant polarizations (Pr) and coercive fields (Ec) display the “U” shaped curve as the BT content changes from 10 mol% to 80 mol%. Finally, according to the similar variation of these key parameters mentioned above, a polarization mismatched model, which describes the destruction and reestablishment of the long range order arrangement in solid solutions composed of two kinds of ferroelectrics, is proposed to illustrate the underlying mechanism. In this PZN-BT system or other similar ABO3-type perovskite relaxors, the competition between the A-O and B-O coupling plays an important role to form the “U” shaped evolution of these key parameters.

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Держатели документа:
Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic and In formation Engineering, Xi'an Jiaotong University, Xi'an, China
Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk, Russian Federation
Institute of Engineering Physics and Radio Electronics, Siberian Federal University, Krasnoyarsk, Russian Federation
State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China
School of Natural Sciences and Mathematics, Ural Federal University, Ekaterinburg, Russian Federation

Доп.точки доступа:
Gao, Q.; Hu, Q.; Jin, L.; Gorev, M. V.; Горев, Михаил Васильевич; Chezganov, D. S.; Vlasov, E. O.; Zeng, H.; Zhao, L.; Cui, Y.; Xu, Z.; Wei, X.
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