Doping of KDP single crystals with cerium: Growth and optical properties

The features of doping of KDP crystals with cerium ions and organocerium complexes with alizarin complexon and arsenazo III have been investigated. It is established that “direct” doping by introducing cerium salts into the initial solution cannot be implemented. The effect of organometallic complexes of cerium on the crystal growth has been studied. Organocerium complexes predominantly enter the prismatic or pyramidal growth sectors. It is shown that the complex arsenazo III + Ce blocks the growth of the prismatic sector. Cerium-doped KDP crystals exhibit a photoluminescence band peaking at the wavelength λ_max= 350 nm.     

Structures of 2-hydroxypyridine and its vinyl derivatives

The PMR, Raman, and UV absorption spectra of 2-hydroxypyridine and its vinyl derivatives were investigated. Their electrochemical reduction was studied, and a quantum-chemical analysis of them was performed. It was concluded that the structure of 2-hydroxypyridine in proton-donor solvents is mesomeric, and its wave function, to a first approximation, is a linear combination of the wave functions of the 2-pyridone and zwitterion models. The contribution of the wave functions of each of the models depends substantially on the concentration of the solution and the nature of the solvent. An assumption was made regarding the presence of dynamic conjugation between the vinyl group and the ring in vinyl derivatives of 2-hydroxypyridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 95–102 January, 1972.     

Reaction of 1,2,4-triazole-3-thione with acetylene

A mixture of 1,2,4-triazol-3-yl vinyl sulfide and N,S-divinyl derivatives is formed in the reaction of 1,2,4-triazole-3-thione with acetylene under pressure. The mixture of N,S-divinyl derivatives was separated into two isomers by gas-liquid chromatography. The hydrogenation, polymerization, and complexing of 1,2,4-triazol-3-yl vinyl sulfide were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1561–1563, November, 1977.     

15N NMR spectra and specific intramolecular interactions in N-vinylazoles

The factors that affect the chemical shifts in the ¹⁵N NMR spectra of N-vinylazoles were investigated. It was shown that an additional positive contribution to the shielding constant of the pyridine nitrogen atom occurs in the s-cis-(N₍₂₎) conformation of N-vinylpyrazoles due to overlapping of the electron cloud of its unshared electron pair and the s-orbital of the vinyl group hydrogen -cis-atom.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1055–1059, August, 1991.     

Change in the Structure and Corrosion Resistance of a Nickel-Chrome Coating on Stainless Steel During Implantation of High Energy Al+ and B+ Ions

Russian Physics Journal - Magnetron sputtering, vacuum arc deposition, and ion implantation have been used to create a three-layer anti-corrosive coating structure on stainless steel samples. The...     

Surface Conductivity of the Ytterbium-Doped Topological Kondo-Insulator SmB6

Doklady Physics - The temperature dependence of the conductivity of the topological Kondo-insulator (TKI) Sm1 – xYbxB6 is investigated in the temperature range 2 < T < 300 K for...     

Anomalies in the variation of elastic properties of cesium during phase transformations under a pressure up to 5 GPa

The pulsed ultrasonic method is used for studying polycrystalline cesium under a pressure up to 5 GPa. Elastic parameters and compression ratio of cesium are determined and anomalies in the elastic properties of cesium during phase transitions CsI-CsII-CsIII-CsIV are revealed. It is found that the CsII-CsIII electron-structure transformation is preceded by anomalous compressibility of the fcc phase of cesium and by softening of longitudinal and transverse acoustic modes of the cesium phonon spectrum.     

Fast etching and metallization of SiC ceramics with copper-vapor-laser radiation

The etching of polycrystalline SiC is studied with the help of radiation of a copper-vapor laser either in air or under the layer of a liquid (H₂O, DMSO). The etching rate in air is as high as 0.24 m/pulse, in DMSO 0.07 gm/pulse at an energy density of 16 J/cm². The etched surface is characterized with Scanning Electron Microscopy (SEM) and X-ray diffractometry. Etching of SiC ceramics in air revealed the partial amorphization of SiC and the formation of microcrystals of elementary Si with an average size of 300 Å. The etched surface of SiC ceramics takes on the ability to reduce Cu from a corresponding electroless plating solution. The adherence of the deposit is as high as 30 N/mm² and is a function of the scanning velocity of the laser beam.     

Ultra-high efficiency multilayer blazed gratings through deposition kinetic control

Diffraction efficiency of multilayer-coated blazed gratings (MBG) strongly depends on the perfection of the sawtooth-shaped layers in the overall composite structure. Growth of multilayers on sawtooth substrates should be carefully optimized to reduce groove profile distortion and, at the same time, to avoid significant roughening of multilayer interfaces. In this work, we report on a way to optimize growth of sputter-deposited Mo/Si multilayers on sawtooth substrates through variation of the sputtering gas pressure. We believe a new record for diffraction efficiency of 44% was achieved for an optimized MBG with groove density of 5250 lines/mm at the wavelength of 13.1 nm.