A new concept of a generalized solution of operator equations in a Banach space

We define a new notion of a generalized solution of an operator equation with a closed linear operator in a Banach space as an element of the completion of this space with respect to some locally convex topology. We prove a theorem on the existence and uniqueness of the generalized solution. Bibliography: 5 titles. Translated fromObchyslyuval'na ta Prykladna Matematyka, No. 81, 1997, pp. 93–99.     

Structural defects in 6H-SiC substrates and their effect on the sublimation growth of epitaxial layers in vacuum

The structural perfection of silicon carbide substrates and homoepitaxial layers grown on the substrates by sublimation has been studied by x-ray diffraction (topography and diffractometry) and optical microscopy. The optimum diffraction conditions (hkil reflections, radiation wavelength λ, and recording geometry) for revealing “micropipes” of the dislocation nature are determined. It is shown that the growth conditions used make it possible to obtain highly perfect epitaxial layers.     

On the Approximation of Functions by Random Splines of Minimal Defect

We consider the problem on the approximation of a function of the class by interpolation splines of order m and of minimal defect in the case where values of the function are known with random errors at nodes of the interpolation. We study the random error of such an approximation.     

Structuring effect of heteroepitaxial CdHgTe/CdZnTe systems under irradiation with silver ions

The characteristics of a damaged layer of p-Cd _x Hg_{1 ? x} Te/CdZnTe (x ～ 0.223) heterostructures after implantation by 100-keV silver ions with the implantation dose Q = 3.0 × 10¹³ cm^?2 have been obtained using X-ray diffraction, atomic force microscopy, and electron microscopy. It has been found that, as a result of the ion implantation and subsequent annealing (75°C), a uniform array of nanostructures is formed on the surface of Hg(Cd)Te/Zn(Cd)Te samples. The X-ray diffraction patterns of the structurized Hg(Cd)Te/Zn(Cd)Te sample indicate the formation of polycrystalline Hg(Cd)Te phases of cubic structure with a composition x ～ 0.20 and also oxide Ag₂O in the subsurface (<100 nm) region of the host material. The observed effects of transformation of the defect-impurity system and structuring of the surface of the heteroepitaxial film of the low-energy-gap semiconductor have been explained using a deformation model.     

Synthesis and Spin State of the Cobalt(II) Complexes with Substituted 2,6-Bis(pyrazol-3-yl)pyridine Ligands

Russian Journal of Coordination Chemistry - The direct template reactions afford the cobalt(II) complexes (I–III) with the hydroxy- and acetyl-substituted 2,6-bis(pyrazol-3-yl)pyridine...     

Ion-plasma treatment of Cd1 ? x Zn x Te (x ～ 0.04) single crystals and application of antireflection diamond-like carbon films

The influence of ion-plasma treatment of Cd_{1 ? x} Zn _x Te (x ?? 0.04) single crystals, which precedes the deposition of an antireflection coating (a diamond-like a-C: H: N film) on the optical properties of the resulting structure, is investigated. Treatment is carried out in an argon, nitrogen, and hydrogen plasma. As follows from the optical properties of the a-C: H: N/Cd_{1 ? x} Zn _x Te, the structure treated in an argon plasma offers the highest transmission. A model of the optical system is proposed that takes into account the formation of transition layers after ion-plasma treatment and the effect of the type of ion on their characteristics. The absorption spectra of the a-C: H: N/Cd_{1 ? x} Zn _x Te system are analyzed, and bands assigned to the stretching and bending vibrations of C-H bonds, as well as to C-C and C=O bonds, are revealed. The presence of these bonds should be taken into account in designing and synthesizing these optical coatings.     

Approximation of continuous functions with random errors in observed values

We consider the problem of approximation of continuous functions by generalized polynomials in the case where the values of the function at the observation points are known with random errors. We construct confidence limits with a given significance level for the true values of the function at any point of its domain of definition. Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 50, No. 9, pp. 1244–1249, September, 1998.     

New Wannier-Stark localization effects in natural 6H-SiC superlattice

A premature electric breakdown caused by the formation of a strong-field domain under conditions of negative differential conductivity in the 6H-SiC n⁺-n^?-n⁺ structure optimized for ultrahigh-frequency measurements was observed in the range of electric fields corresponding to the Bloch oscillation regime in a natural 6H-SiC superlattice. The experimental results and ensuing estimates indicate that this domain is mobile and, hence, oscillating, allowing the microwave oscillations that are rapidly damped under conditions of avalanche break-down in a natural 6H-SiC superlattice to be forecasted. Crystal perfectness of a natural 6H-SiC superlattice made it possible to directly observe the Wannier-Stark localization up to electric breakdown, i.e., during the natural crystal lifetime. This was accomplished by the optical photoelectric transformation method in the multiplication regime for a photocurrent created by photons with above-bandgap energy. It was shown that the Wannier-Stark localization, which involves only electrons, occurs in natural 6H-SiC superlattice up to fields that are almost equal to the breakdown field in 6H-SiC, unresponsively to band mixing, i.e., to the fundamental destroyer of the Wannier-Stark localization.     

A Trigonal Prismatic Cobalt(II) Complex as a Single Molecule Magnet with a Reduced Contribution from Quantum Tunneling

Herein, we report a new trigonal prismatic cobalt(II) complex that behaves as a single molecule magnet. The obtained zero-field splitting, which is also directly accessed by THz-EPR spectroscopy (−102.5 cm⁻¹), results in a large magnetization reversal barrier U of 205 cm⁻¹. Its effective value, however, is much lower (101 cm⁻¹), even though there is practically no contribution from quantum tunneling to magnetization relaxation.     

Setup parameters controlling the growth rate of silicon carbide epitaxial layers in a vacuum

An extension of the model suggested in [5] allows us to consider the influence of the growth cell geometry, as well as temperature and pressure gradients, on the growth rate of SiC epitaxial layers in a vacuum. The experimental dependences of the substrate temperature on the current in an induction coil that are taken for different positions of the cell relative to the inductor are discussed.