Research papers
Díaz-Flores, L. L. Structure and Optical Properties of Nanocomposites Prepared by the Incorporation of Organic Dyes into a SiO2 and SiO2–PMMA Glassy Matrix / L. L. Díaz-Flores, J. F. Pérez-Robles, P. Y. Vorobiev, P. P. Horley, R. V. Zakharchenko, J. González-Hernández, Yu. V. Vorobiev // Inorganic Materials. – 2003. - Vol. 39. - No. 6. - P. 631–639. | Print |
Written by Paltsun   
Sunday, 11 May 2014 17:01

Electronic spectra of nine different types of organic colorants embedded in three different matrices (sol–gel SiO2, PMMA, and SiO2–PMMA) were studied experimentally with the use of optical absorption, photoluminescence excitation, and emission techniques, as well as fluorescent microscopy and atomic force microscopy. We found a distinct set of energy levels for each type of dye. The type of matrix and the degree of aggregation of the organic molecules have relatively small effects on the spectra, although their influence on the optical density of the material is essential. The character of the energy spectra is mainly related with the shape of the dye molecule. A quantum mechanical description of the electronic spectra of these molecules was made on the basis of the free electron molecular orbitals approach. The molecules were considered as two dimensional potential wells with different shapes. The effect of boundary conditions on the energy spectra was studied. The direct solution of the Schrödinger equation shows a good theory–experiment correlation. (text)

Last Updated on Sunday, 11 May 2014 17:04
Воробьев, Ю. В. Влияние электрического поля на неравновесные процессы в полупроводниковом алмазе / Ю. В. Воробьев, В. Н. Захарченко, Р. В. Захарченко, Б. К. Рао // Письма в ЖТФ. - 1996. - Том 22. - Вып. 11. - С. 76-80. | Print |
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Sunday, 11 May 2014 16:53

The equilibrium and nonequilibrium electrical conductivity of synthetic diamond is studied in the temperature range 300-400 K in weak and strong electric fields. Its optical characteristics are also investigated. It is found that two types of local centers appear in nonequilibrium processes: acceptors with the level Ev +0,4 eV and donors with a level approximately in the middle of the bandgap. Both dark conductivity and photoconductivity are transported by holes. It is observed that the depth of the acceptor centers is reduced in a strong electric field, which may be caused by field ionization of excited states of a hydrogen-like center. (text)

Last Updated on Sunday, 11 May 2014 17:05
Vorobiev, Yu. V. Electrical and optical properties of non-uniform semiconducting synthetic diamond with deep impurity levels [Текст] / Yu.V. Vorobiev, R.V. Zakharchenko, G.N. Semenova, A.V. Svitelskiy, T.V. Torchinskaya // In Proceedings of Semiconducting and Semi-Insulating Materials Conference. IEEE Publication Date: 29 Apr-3 May 1996. – 1996. - Toulouse, France. – P. 307-310. | Print |
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Sunday, 11 May 2014 16:42

Synthetic boron-doped p-type single crystals of diamond possess a low-resistance surface layer. The photoconductivity of the bulk high-ohmic region exponentially increases with the increase of temperature. The activation energy of this dependence is 0,4 eV at low electric field and 0,3 eV at high field. The change of activation energy is explained on the basis of the hydrogen-like model of the boron acceptor center. In high electric field the electric current instability is observed connected with the deep levels recharging and thermal breakdown phenomena. (text)

Last Updated on Sunday, 11 May 2014 16:53
Yu.I. Gorobets, S.O.Reshetnyak. Bulk Spin-Wave Filtration at the Interface of Two Uniaxial Ferromagnetic Media // Journal of Nano- and Electronic Physics. –2012. – V. 4, № 2. – С. 02001-02003 (3pp). | Print |
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Saturday, 10 May 2014 16:27

In this paper the dependencies are obtained of spin wave reflection coefficients on frequency and external magnetic field for ferromagnetic structure in the exchange mode, when the influence of magnetostatic part of energy is neglected as compared with exchange one. It is shown that ferrogarnet structure, having very small damping parameter, is good for high-quality filtration of spin waves because it gives large change of reflection coefficient in small intervals of frequencies and external magnetic fields.

Last Updated on Saturday, 10 May 2014 16:41
S. Reshetnyak, A. Berezhinsky. Reflection and refraction of bulk exchange spin wave on the interface of two ferromagnetic media in planar magnetic field // Global Journal of Science Frontier Research. – - 2012. –V. 12, Issue 3. – P. 61-64 | Print |
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Saturday, 10 May 2014 16:22

Behavior of spin wave propagation in ferromagnetic medium with non-uniform distribution of magnetic parameters is studied. In particular, the influence of external magnetic field on behavior of bulk spin wave propagating through inhomogeneity made in form of lens (lens is biaxial ferromagnet placed into biaxial ferromagnetic medium with another magnetic parameters; ferromagnets are in the homogeneous magnetic field directed along the hard axis) is studied.

Last Updated on Saturday, 10 May 2014 16:41

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