A. S. Tver’yanovich

The effect of carbon nanoparticles on the thermal and photolytic properties of the (5-nitrotetrazolato-N2) pentaammin-cobalt(III) perchlorate complex

The problem of modifying thermal and photolytic properties by using carbon nanoparticles is discussed for an energy-saturated (5-nitrotetrazolato-N2) pentaammin-cobalt(III) perchlorate metal complex. The interpretation of the experimental data using the conception of minor structural transformations is proposed.

Mechanism of a microwave-assisted polyol synthesis of nanosize CuInSe2 particles and their optical and photoelectric properties

Mechanism of the reaction in which CuInSe2 nanoparticles are formed in synthesis by the microwaveassisted polyol method was studied. The morphology and optical properties of thin layers (films) produced from the synthesized CuInSe2 nanoparticles and the morphology and photoelectric properties of composite films based on CuInSe2 and [6,6]phenyl C61 butyric acid methyl ester were examined. It is shown that CuInSe2 nanoparticles can be used to form a photo-absorbing layer in composite organo-inorganic solar cells.

Synthesis of nanocrystalline powders of yttrium aluminum garnet doped by neodymium

Nanocrystalline powders of yttrium aluminum garnet were synthesized by the decomposition of gel formed by citrate metal complexes with ethylene glycol (the Pechini method). Using the Pechini method, it was possible to synthesize nanocrystalline garnet powders at a lower temperature than using the traditional coprecipitation of hydroxocarbonates. X-ray diffraction data showed that the size of coherent scattering of X-ray for the powders changes from 15 to 30 nm depending on the temperature and duration of synthesis. The crystalline phase of garnet is single in all nanocrystalline powders. The results of the studies suggest that the Pechini method makes it possible to obtain nanocrystalline sample powders at lower temperatures than those used in the traditional synthesis from coprecipitated hydroxocarbonates. The CSR size in the prepared powders depends on the synthesis conditions and ranges from 15 to 30 nm. Luminescence spectra and X-electronic spectra showed that short range order in amorphous powders is the same as in garnet crystal. The optimal conditions for powders as ceramic precursors are a temperature of 1000°C and treatment for from 2 to 4 h.

Composition investigation of lithium niobate crystals and its influence on the optical damage resistance

Optical methods of investigation of the defect structures and the composition of lithium niobate (LiNbO3) single crystalsis discussed. The intrinsic defects concentrations in lithium niobate crystals (lithium vacancies (VLi)− and (NbLi)4+ defects, Nb on Li site in the valence state 4+), as a function of the Li/Nb ratio, are also reported. The optical damage resistance of various lithium niobate samples was investigated as a function of the composition. A remarkable increase in the optical damage resistance was found in MgO-doped almost stoichiometric lithium niobate crystals.

Specific optical and photoelectric properties of thin CuIn3Se5 films synthesized by laser deposition

Optical and photovoltaic properties of films produced by laser deposition of CuIn3Se5 and the effect of the temperature conditions of film synthesis on these properties are studied. The composition of the films deposited onto substrates held at room temperature coincides with that of the target, with the films obtained in the vitreous state. Heating of substrates during deposition leads to a larger fraction of the crystalline phase and lower fraction of Se in a film. Annealing of glassy CuIn3Se5 films in a vacuum at temperatures of up to 700 K causes their crystallization without changes in composition. The photosensitivity of the films is highest at annealing temperatures of 510–600 K.

Laser Initiation of Photo- and Thermal Processes on a Pentaammine (5-Nytrotetrazolato-N2) Cobalt(III) Perchlorate Example

Microscopic mechanisms of photo- and thermal structural transformations initiated by laser radiation are considered. The results obtained are illustrated on an energy-saturated metal complex of pentaamine (5-nytrotetrazolato-N2) cobalt(III) perchlorate and its fullerene modifications.

Chalcogenide glass for AgI-based nanolayered films

Glass in the system GeSe2–Sb2Se3–AgI in monolith and film states has been investigated. Special attention has been paid to the crystallization stability and ionic conductivity of glass and films. The films were fabricated by the laser ablation of glass in a vacuum. The fabricated glass has been studied by the methods of X-ray diffraction and differential thermal analyses and impedance measurement. The sputtered films have been studied by X-ray diffraction and Raman spectroscopy in order to control their stability to crystallization and to compare their structure with that of monolith glass. It has been demonstrated that glass containing 40 mol % AgI is characterized with the softening point that is substantial for chalcogenide glass (190°C) and high crystallization stability, whereas the logarithm of their specific conductivity at 100°C is a value of the order of–3.5 at the activation energy of around 0.5 eV.

As39S6 films as protein-selective two-dimensional arrays for biochips

Due to the photoresistive properties of films in the As-S system, a two-dimensional array has been formed on a glass substrate using islands of this film. The adhesion of protein materials with fluorescent dyes to the structure obtained was studied. Selective adhesion of protein molecules to islands of a chalcogenide film has been found. The protein markers adsorbed on the film are resistant to prolonged washing in a buffer isotonic solution and water. The results obtained indicate prospects in the study of these films as a material for substrates of protein biochips.

Vitreous Films of Ga 6 Ge 17 S 43 Composition as a Biochip Substrate

Adhesion of protein materials with fluorescent stains to the film of Ga6Ge17S43 composition fabricated by the pulsed laser deposition was investigated. Resistance of the protein markers deposited onto the film to a washing in buffer isotonic solution was established. The obtained results provide the possibility to use these films for the development of protein biochips.