On elastic deformation of the indentation surface in alkali-haloid crystals

It is demonstrated experimentally that in the microindentation process, elastic deformation takes place of the crystal surface region under load containing the forming imprint. A technique is proposed for determining this elastic deformation in alkali-haloid crystals.     

Electromechanical properties of Pb<Subscript>3</Subscript>Ga<Subscript>2</Subscript>Ge<Subscript>4</Subscript>O<Subscript>14</Subscript> piezoelectric crystals grown from solution in a melt

Single crystals of lead gallium germanate Pb₃Ga₂Ge₄O₁₄ are grown from their own solution melts. The propagation of bulk acoustic waves is investigated, and the elastic, piezoelectric, and dielectric constants are calculated. The temperature dependences of the dielectric constants of this compound are analyzed.     

Calculation of the spectra of potassium-like multicharged ions

The energy levels and oscillator strengths for dipole transitions between the levels of low-lying configurations are calculated for ions of the KI isoelectronic sequence. The calculations are based on the energy approach to the effective potential method with the most important polarization effects taken into account, including core polarization by the outer electron. The results, some of which are obtained here for the first time for potassium-like ions, can be useful in a number of related fields, such as laser physics, plasmas, and so on.Odessa Hydrometeorological Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 3–9, November, 1992.     

Correlation corrections based on the Schrödinger equation with a local potential

A compromise version of calculation of the ground state electronic energy is proposed that combines both the density functional theory and the wave function formalism. Single-particle orbitals and energies are determined by solving the Kohn-Sham equations with a local effective potential, which depends on the parameters determined by the variational principle. Correlation corrections are calculated using the Rayleigh-Schrödinger perturbation theory in the zero-order approximation of the Möller-Plesset theory. The specific features of the expressions for the corrections to the wave function and the energy determined in terms of the Kohn-Sham orbitals are considered. This approach, in contrast to the well-known optimized effective potential method, can be applied with equal computational expenditures to both atoms and molecules. A comparative analysis for 20 helium-like atoms showed that the scheme proposed provides better agreement with the “exact” values of the energy in the second order of the perturbation theory in comparison with the results obtained using the conventional exchange-correlation potentials BLYP and PW91. A similar trend is also observed for diatomic hydrides (from LiH to FH), although, in contrast to the atoms, the deviations from the experimental estimates of the energy are less systematic.     

An observation of electron phase transition in SmB6 at low temperatures

In order to reveal the nature of the ground state of archetypal intermediate-valence compound SmB₆, a comprehensive study of its transport and magnetic properties was carried out on high-quality single crystals at temperatures of 1.8-300 K in magnetic fields up to 7 T. A drastic enhancement of negative magnetoresistance was observed below 14 K, with the maximum absolute value of Δρ/ρB²∼2.2×10⁻³ T⁻² at T≈5.2 K. This effect seems to be attributable to anomalous magnetic scattering of many-body (exciton-polaronic) complexes induced by fast valence fluctuations on Sm sites. The observed anomalies of magnetotransport, thermoelectric and magnetic characteristics are discussed in terms of electron phase transition to the coherent state of interacting many-body complexes occurring at T^*∼5 K.     

Synthesis and structure of 5,5-dialkyl-3-arylamino-2-thiohydantoins

The reaction of arylhydrazides of -alkyl--chlorocarboxylic acids with thiocyanate ions gave intermediate thiocyanates which rearranged to isothiocyanates on heating and the latter cyclized to 5,5-dialkyl-3-arylamino-2-thiohydantoins.Institute of Technical Chemistry, Urals Branch, Russian Academy of Sciences, Perm' 614000. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 898–903, July, 1997.     

Azines of the Isoquinoline Series: III. Reactions of Substituted 1-Hydrazono-3,4-dihydroisoquinolines with Dicarbonyl Compounds

3,3-Dimethyl-1-hydrazono-1,2,3,4-tetrahydroisoquinoline derivatives react with benzil in 1 : 1 or 2 : 1 ratio to give the corresponding benzil monohydrazones. Diacetyl under the same conditions forms dihydrazones. Enolizing 1,3-dicarbonyl compounds form with 3,3-dimethyl-1-hydrazono-1,2,3,4-tetrahydroisoquinoline derivatives mixtures of mono- and dihydrazones. Dehydracetic acid forms monohydrazones at the exochain carbonyl group.     

The studies of the effect of photostimulated changes in thin carbon films

Photostimulated changes in thin carbon films deposited onto fused silica substrates by reactive magnetron sputtering and irradiated by the light of the first (1060nm) and the second (530nm) harmonics of a QW-switched Nd³⁺ AVG laser were investigated. The changes are supposed to be connected with the reordering of chemical bounds.