Excitons in ZnP2 crystals in the electric field of a Schottky barrier

A study is made of the effect of electric fields on the exciton states of β-ZnP₂ crystals (T=77 K) in structures with Schottky barriers formed by depositing semitransparent electrically-conducting InSnO₂ films on the crystal surface. The observed changes in the exciton optical reflection spectra when an electrical potential is applied to a barrier are explained by the shift and broadening of the exciton level caused by the Stark effect. The experimental data are compared with calculations based on a theory of exciton optical reflection from planar spatially nonuniform structures. Fiz. Tverd. Tela (St. Petersburg) 40, 884–886 (May 1998)     

Chemical composition and structure of the surface layers-products of interaction between steel 3 and hostile aqueous environment: The effect of the environment

The composition and structure of layers formed by corrosion products at the open-circuit and passive potentials on the surface of steel 3 in aqueous media containing sulfate ions, borate ions, or their mixtures are studied by X-ray photoelectron spectroscopy and secondary ion mass spectrometry. The composition and structure of both the phase surface layers and the adsorption surface layers are found to depend on the solution nature. The composition and structure of a corrosion product layer; the composition of the double layer, in particular, the surface charge and potential; and the anion role as a corrosion inhibitor or activator depend on the way the anion coordinates with the corroding-metal surface. The coordination may be strong, in an inner coordination sphere (borate ions), or less strong, in an outer coordination sphere (sulfate ions) of a cation on the surface.     

Epitaxial gallium oxide on a SiC/Si substrate

Well-textured gallium oxide β-Ga₂O₃ layers with a thickness of ~1 μm and a close to epitaxial layer structure were grown by the method of chloride vapor phase epitaxy on Si(111) wafers with a nano-SiC buffer layer. In order to improve the growth, a high-quality silicon carbide buffer layer ~100 nm thick was preliminarily synthesized by the substitution of atoms on the silicon surface. The β-Ga₂O₃ films were thoroughly investigated using reflection high-energy electron diffraction, ellipsometry, X-ray diffraction, scanning electron microscopy, and micro-Raman spectroscopy. The investigations revealed that the films are textured with a close to epitaxial structure and consist of a pure β-phase Ga₂O₃ with the (\(\overline 2 01\)) orientation. The dependence of the dielectric constant of epitaxial β-Ga₂O₃ on the photon energy ranging from 0.7 to 6.5 eV in the isotropic approximation was measured.     

Experimental investigation of liquid drop evaporation on a heated solid surface

Evaporation of a water drop was studied experimentally at a temperature difference between the solid surface and surrounding atmosphere from 30 to 60 °C. The studies were performed on the substrates with micro- and nanocoatings with different wettability. The features of evaporation were studied for the pinned, partially pinned, and depinned three-phase contact line (solid-liquid?gas interface). It is shown that with a decrease in the water drop volume, the specific evaporation rate (mass flow per unit of surface area) increases, particularly at the last stage of evaporation.     

In memory of our authors

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In memory of our authors     

Photoluminescence of thin amorphous-nanocrystalline silicon films

Photoluminescence spectra of thin hydrogenated-silicon films having mixed amorphous-nanocrystalline phase composition have been studied. Fabry-Perot interference was found to affect strongly the shape of the spectra. An analysis of the spectra made with inclusion of interference corrections shows that only one emission band forms in the 0.6–1.0 μm region due to carrier recombination at centers of the same type. Fiz. Tverd. Tela (St. Petersburg) 41, 153–158 (January 1999)     

Two-Stage Conversion of Silicon to Nanostructured Carbon by the Method of Coordinated Atomic Substitution

Physics of the Solid State - A fundamentally new method of obtaining epitaxial layers of nanostructured carbon on silicon substrates has been considered. Epitaxial growth in the case of seemingly...     

Precompression of matter during radiative energy transfer in a steady-state thermonuclear burn wave

It is shown that precompression of matter ahead of the thermonuclear burn wave front can occur in the central volume of a multilayer cylindrical system under conditions of radiative energy transfer outside the region of wave propagation. The degree of compression is sufficient for the development of a self-maintained wave of fusion reactions. Pis’ma Zh. éksp. Teor. Fiz. 66, No. 12, 783–786 (25 December 1997)