Variation of the Vibration and Electronic States at Ion Irradiation of TiO2 Nanofilms with Ag and Au Nanoparticles

The nonmonotonic dependence of the intensities of vibrational lines in the Raman scattering of TiO2 nanofilms, including Ag and Au nanoparticles, from the irradiation dose D by Ti+ (140 keV) ions was estab-lished. The increase of the intensity in 1.3-1.5 times for TiO2 films at D 1012 - 1013 ions/cm2 related with improved of films structure at low doses. The enhancement of low-frequency electronic bands with dose in-creasing was study. It was shown that the effect of plasmon is not a major and the vibrational-electronic interaction plays the main function. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3529

The short-range order and its influence on radiation stability of low-concentration Fe-Cr alloys

The analysis of the structural phase state of Fe-Cr low concentration solid solutions and steel 1X13, associated with the formation of short-range order (SRO) of various types in them has been performed at the mesoscopic level. A comparison of the SRO and swelling of alloys under irradiation was carried out. It was shown that there is a fairly good qualitative correlation between them.Проаналізовано на мезоскопічному рівні структурно-фазовий стан низькоконцентраційних твердих розчинів Fe-Cr та сталі 1Х13 у зв’язку з утворенням у них близького порядку різних типів. Проведено порівняння ступеня близького порядку та величини розпухання сплавів при опроміненні. Показано, що між ними має місце досить добра якісна кореляція.Проанализировано на мезоскопическом уровне структурно-фазовое состояние низкоконцентрационных твердых растворов Fe-Cr и стали 1Х13 в связи с образованием в них ближнего порядка различных типов. Проведено сравнение степени ближнего порядка и величины распухания сплавов при облучении. Показано, что между ними наблюдается довольно хорошая качественная корреляция

S-matrices for Perturbed N=2 Superconformal Field Theory from quantum groups

S-matrices for integrable perturbations of $N=2$ superconformal field theories are studied. The models we consider correspond to perturbations of the coset theory $G_k \times H_{g-h} /H_{k+g-h}$. The perturbed models are closely related to $\hat G$-affine Toda theories with a background charge tuned to $H$. Using the quantum group restriction of the affine Toda theories we derive the S-matrix.Comment: 29 pages 2 figure

Lattice Analogues of N=2N=2 Superconformal Models via Quantum Group Truncation

We obtain lattice models whose continuum limits correspond to $N=2$ superconformal coset models. This is done by taking the well known vertex model whose continuum limit is the $G \times G/G$ conformal field theory, and twisting the transfer matrix and modifying the quantum group truncation. We find that the natural order parameters of the new models are precisely the chiral primary fields. The integrable perturbations of the conformal field theory limit also have natural counterparts in the lattice formulation, and these can be incorporated into an affine quantum group structure. The topological, twisted $N=2$ superconformal models also have lattice analogues, and these emerge as an intermediate part of our analysis.Comment: 25 pages and 2 figure

Features of special joints of grain boundaries in polysilicon films of equiaxial and dendritic structures

Comparative analysis of special grain boundary joints in polysilicon films with equiaxial and dendritic (undoped and phosphorus-doped) structure, prepared by low-pressure chemical vapor deposition, has been carried out using atomic force microscopy and transmission electron microscopy. The formation mechanisms of special grain boundary joints have been analyzed for different film structures. The effect of phosphorus on formation of grain boundary joints has been analyzed.Методами атомной силовой микроскопии и просвечивающей электронной микроскопии проведен сравнительный анализ специальных стыков границ зерен в поликристал-лических пленках кремния с равноосной и дендритной структурой (нелегированных и легированных фосфором), полученных методом химического осаждения из газовой фазы в реакторе пониженного давления. Рассмотрены механизмы формирования специальных стыков в пленках разных структурных модификаций. Проанализирована роль фосфора в формировании стыков границ зерен.Методами атомної силової мікроскопії та просвічуючої електронної мікроскопії проведено порівняльний аналіз спеціальних стиків границь зерен та поверхневих неоднорідностей у полікристалічних плівках кремнію з рівноосьовою та дендритною структурою (нелегованих і легованих фосфором), отриманих методом хімічного осадження з газової фази в реакторі зниженого тиску. Розглянуто механізми формування спеціальних стиків у плівках різних структурних модифікацій. Проаналізовано роль фосфору у формуванні стиків границь зерен

Photocatalysis by TiO₂ films at structure relaxation

The crystalline and electron structure of TiO₂ and TiO₂/ZrO₂/SiO₂ coating obtained by sol-gel technique and annealed at 773 K and 873 K has been studied. The film synthesis and further heat treatment result in formation of nano-sized anatase particles with a developed surface and shallow and deep traps within the band gap of titania. Rater localized electron states correspond to these defects, which result in occurrence of some new optical absorption bands. Some of the optical conductivity bands belong to oxygen vacancies which are deep defects, and the other ones are connected with surface defects. The nature of surface defects should be various. The presence of shallow defects deforms the edge of conductive band, tailing it

⁶³Ni diffusion in C₆₀ fullerite

The possibility to obtain in principle metal-fullerides using diffusion methods has been established using radioactive isotopes (⁶³Ni). The thermally activated diffusion (T = 300°C) in fullerite crystal has been assumed to occur according to the interstitial mechanism via successive filling of octa- and tetrahedral pores. The basic quantitative characteristics of diffusion in a fullerite crystal: diffusion coefficient D ~ 10⁻¹² cm²/s,β radiation absorptance in fullerite µ = 3.94*104 cm-1 and dynamics of its diffusion saturation with the metal atoms have been determined

Composite "graphene nanoplatelets - fluorine-containing polyamide": synthesis, properties and quantum-chemical simulation of electroconductivity

Considered in the article is the basic possibility of increasing of electric conductivity of thermostable fluorine-containing aromatic polyamide by its doping with graphene platelets. The raised concentration of a conducting graphene phase (78 wt.%) in the top layer (~ 50 μm) of the film composite is established. The microstructure of cross-section of the film and topography of its surface are studied by SEM and AFM. Corresponding volt-ampere characteristics are resulted. Carried out here are quantum-chemical calculations of model system &qout;a polyamide fragment + graphene strip&qout;: localization of boundary and close molecular orbitals in the composite and also distribution of spin density of the composite in electric field. Conductivity of the composite is explained within the framework of stacking interaction between π-systems of the polymer and graphene

Radiative recombination of the PVK/C60 molecular complexes with the radiation damages

The relaxation processes of electronic excitations in the films composed from a mixture of the amorphous semiconductors of polyvinylcarbazole and C₆₀ fullerenes (PVC/C₆₀) with different contents of nanocluster molecules and beyond the threshold electron irradiation are studied. It is shown that, in the entire range of the concentrations of C₆₀ molecules, for which the molecular disperse state of a mixture retains, the complexes with the charge transfer due to the photogeneration of electron-hole pairs are observed in the PVC/C₆₀ films. The photoluminescence spectra indicate the presence of both the molecular emitting transitions and the recombination luminescence caused by the electron transfer in the composition of excitons from the matrix to impurity fullerenes. Depending on the content of C₆₀ molecules, the photoluminescence spectra are substantially reconstructed, reflecting the changes in the electron structure of molecular complexes. The nature of these changes retains with the introduction of radiation-induced damages under high-energy electron irradiation with an absorbed dose of 3.0 MGy

Ganges in crystal structure of fullerene films at alloying and radiation defect formation

The crystal structure of the C₆₀ fullerene films with their alloying by the oxygen molecules and copper atoms in studied and under the influence of high energy eletron irradiation (Ee = 1.8 MeV) is investigated. It is shown that the crystal structure of the C₆₀ and C₇₀ films changes in the dependence on the concentration of impurity elements and radiation damages substantially infuluences the electronic and vibration spectra of fullerenes and is the result of the appearance in this case of additional Coulomb intermolecular interaction