Effect of Mechanical Stress on the Splitting of Spin Sublevels in 4H-SiC

JETP Letters - The effect of static mechanical strain on the splitting of spin sublevels of color centers based on spin 3/2 silicon vacancies in silicon carbide at room temperature has been shown....     

Nickel(ii) N-heterocyclic carbene complexes as efficient catalysts for the Suzuki—Miyaura reaction

Russian Chemical Bulletin - Catalytic activity of nickel(ii) and palladium(ii) N-heterocyclic carbene (NHC) complexes derived from imidazole, benzimidazole, and 1,2,4-triazole was comparatively...     

Oxidative dimerization of alcohols in the presence of nitroxyl radical–iodine catalytic system

Pyridine catalyzes oxidation of alcohols with 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxyl–iodine catalytic system at room temperature. Symmetric esters are formed in good yields.     

Chlorotrimethylsilane-promoted synthesis of 1,2,4-triazolopyrimidines from 3,5-diamino-1,2,4-triazoles and pentane-2,4-diones

An efficient synthesis of 2-amino-1-R-[1,2,4]triazolo[1,5-a]- pyrimidinium or 3-amino-2-R-[1,2,4]triazolo[4,3-a]pyrimidi- nium chloride derivatives by heterocyclization of 3,5-diamino- 1-R-1,2,4-triazoles (R = Alk or Ar) with pentane-2,4-diones was developed. The process is promoted by chlorotrimethyl- silane which plays the dual role of carbonyl-activating agent and water scavenger.     

Formation of a donor profile in silicon upon simultaneous implantation of phosphorus and sodium ions

A four-point probe method was used to study, as the layers were removed consecutively, the concentration distribution profiles of free electrons in high-resistivity p-Si with implanted P⁺ and Na⁺ ions. Anodic oxidation was used to remove layers at a depth of less than 1 μm, and polishing at larger depths. It was shown that the efficiency of diffusion doping of silicon with sodium is determined, to a large extent, by the ratio between the energies of P⁺ and Na⁺ ions. If the conditions are optimal, the efficiency of doping by simultaneous implantation of sodium and phosphorus ions is better (by a factor of 2.5 on the average) than that of doping with Na⁺ ions only.     

Determination of thermoelastic parameters of a layered medium by the photodeflection spectroscopy method

For determining the thermal stresses produced in the film-substrate system under the action of modulated laser radiation, the system of heat conduction equations is solved and the distribution of the potential of thermoelastic forces acting in the media under study is found. Elastic strains and the corresponding stresses are determined, taking into account the initial and boundary conditions, by using the known thermoelastic potentials. The numerical and graphical analysis of thermal stresses is made, which takes into account gyrotropic properties of the film. It is shown that the optical gyrotropy and multibeam interference of eigenwaves in a sample can substantially change the magnitude of photodeflection response of the system. A method for efficient control of the photodeflection signal is proposed, which uses changes in energy, phase, and polarization characteristics of electromagnetic radiation acting on the layered system under study.     

Fluorination of the cubic and hexagonal C60 modifications by crystalline manganese trifluoride

This paper reports on a comparative study of the solid-state fluorination of the cubic and hexagonal fullerene C₆₀ modifications by crystalline manganese trifluoride. It is shown that the variation of the fullerene crystal structure does not noticeably affect the composition of the fluorination products. The enthalpy and entropy of sublimation of the C₆₀ hexagonal phase are experimentally determined for the first time.