Spectroscopy of Zinc Oxide Thin Films near the Fundamental Absorption Edge

Optics and Spectroscopy - The optical absorption spectra of zinc oxide (ZnO) thin films formed by reactive cathode sputtering are studied. The observed absorption of light in the region of photon...     

Synthesis of 2-aryloxy-4,6-bis(4-carboxyphenyl)-sym-triazines and their chlorides

The peculiarities of the reaction of some substituted (in the benzene ring) 2,4-dichloro-6-aryloxy-sym-triazines with toluene under the conditions of the Friedel-Crafts reaction were investigated. Methods for the synthesis of 2-arloxy-4,6-bis(4-carboxyphenyl)-sym-triazines and their chlorides were developed. Cleavage of the ether bond to give a dihydro-sym-triazine structure occurs in the case of 2,4-dichloro-6-benzyloxy-sym-triazine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1125–1129, August, 1983     

Electrical performance of a Ni(II) complex polymer

The I–V characteristics taken of thin films of the oxidized and reduced forms of poly[Ni(Salen)] metallopolymer are studied. The data obtained indicate that states localized in the volume may experience thermofield ionization. It is found that the electroactivity of the oxidized form of the polymer is higher. The parameters of the thermally activated mechanism of charge transfer are determined.     

Specific features of electrical conduction of the poly-[NiSalen] metal-containing polymer thin-film structure

The charge transfer in the oxidized and reduced forms of poly-[NiSalen] metal-containing polymer films is investigated. It is established that the voltage dependence of the differential conductivity for the polymer in the oxidized form exhibits a nonlinear behavior, which indicates a high electrical activity of this state. The microscopic parameters characterizing the charge transfer are calculated within the space-charge-limited current theory. Differences in the surface morphology of two forms of the poly-[NiSalen] films are revealed using atomic-force microscopy.     

On the deformation waves excitation in the process of non-stationary ballistic phonon heat conductivity

Theoretical investigation of deformation waves generation in the process of ballistic phonon heat-pulse propagation is presented. The regime of synchronous excitation of deformation pulse in the zone localized at the moving front of nonstationary phonon flux is forecast.     

Photodielectric Processes in ZnS : Cu Polycrystalline Layers

The frequency dependences of dielectric parameters of zinc sulfide electroluminescent polycrystalline structures doped with copper are studied in the dark and under light excitation in the visible wavelength range. A positive photodielectric effect most pronounced in the low-frequency range was revealed. The experimental results are explained within framework of formation of a space charge in the bulk of a semiconductor. The analysis of data indicates they can be correlated with luminance characteristics of an electroluminescent layer.     

Non-Newtonian dynamics of the fast motion of a magnetic vortex

The dynamics of a magnetic vortex in a thin magnetically soft ferromagnetic disc with a submicron diameter has been analyzed. Under the action of field pulses with a duration of the order of 10–100 ps, the vortex undergoes a complex motion. The analysis of the results of a micromagnetic simulation indicates that this motion is non-Newtonian. It can be described by an equation containing the third time derivative of the displacement of the vortex core.     

Photodielectric effect in thin-film structures of the poly[NiSalen] metallopolymer

This paper reports on the results of investigations of the temperature-frequency dispersion and the kinetics of photodielectric response in metallopolymer structures containing divalent nickel, which have been prepared through electrochemical polymerization. It has been demonstrated that the photodielectric effect observed in the samples under investigation is integral in character due to photoconduction stimulated by light-induced transitions of electrons to the antibonding orbital in the system of π-bonds of the polymer and owing to additional polarization of the nitrogen-containing coordination site of the monomer.     

An origin of light induced centers in the visible range in ferroelectric oxides: possible role of the states of charge transfer vibronic excitons

A light induced absorption peculiarity connected with an absorption peak in the visible range for SBN/Ce was detected. The analysis of these data together with investigation results for a visible range center (VIS-center) absorption study in SBN/Ce and Cr, in nominally pure strontium barium niobate (SBN) as well as in Ba_0.77Ca_0.23TiO₃ crystals give support to charge transfer vibronic excitons (CTVEs) as origin of the phenomenon. While the fast (with relaxation time ∼1 ns at T∼300 K) response can be connected with transitions between excited branches of the adiabatic potential of the CTVE phase, the slow (with relaxation time ∼50 s at T∼230 K for SBN/Cr) response is connected with transitions between ground and first excited CTVE phase branches. The additional contribution to the latter effect due to the absorption of recharged oxygen ions which are in the framework of charge transfer induced by the CTVE cannot be disregarded. The explanation of the main results of the experiments shows that the VIS-center phenomena can be induced by the CTVE-states.     

Reaction of cyanuryl chloride and some of its monosubstituted derivatives with toluene

The Friedel-Crafts reaction of cyanuryl chloride and some of its monosubstituted derivatives with toluene was studied. It is shown that the type and character of the substituent in the 6 position of the starting derivatives of cyanuryl chloride have a strong effect on the course of the reaction. The reaction of cyanuryl chloride and its phenyl and phenoxy derivatives with toluene leads smoothly to the formation of 2,4,6-tris- and 2-substituted 4,6-bis(4-methylphenyl)-sym-triazines. 4,6-Bis(4-methylphenyl)2-oxo-2,3-dihydro-sym-triazine is formed in the case of alkoxy-substituted cyanuryl chlorides. In the case of amino derivatives of cyanuryl chloride the reaction with toluene takes place only upon prolonged refluxing and gives the final products in low yields.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 558–561, April, 1979.