A. N. Ermakov

Structural-morphological transformations in titanium nickelide treated in a nitrogen plasma

Powder heterogeneous mixtures produced from a titanium nickelide powder using a plasma technology are studied by electron microscopy, scanning tunneling microscopy, and X-ray diffraction. The quantitative phase composition and morphological features of the powder mixtures trapped by a vortex cyclone and the surface of a fabric filter are determined.

Recondensation of ferrovanadium and ferromolybdenum in a low-temperature plasma

Ferrovanadium and ferromolybdenum powders are subjected to plasmachemical recondensation in a low-temperature plasma. The synthesized nanocrystalline and ultradispersed compositions are characterized by X-ray diffraction, electron microscopy, and energy dispersive analysis.

Plasmachemical processing of titanium carbide and nickelide in a low-temperature nitrogen plasma

Nanocrystalline TiCN(TiN)-TiNi(Ni) powders are fabricated by plasma processing of a mechanical mixture of titanium carbide TiC and nickelide TiNi. The morphology, topography, phase composition, and elemental composition of the powder particles are studied by scanning electron microscopy, energy dispersive analysis, X-ray diffraction, and scanning tunnel microscopy.

Phase formation and structural characteristics of Cd-Pb-S nanopowder compositions produced by modification of CdS powder in a citrate-ammonia solution of a lead salt

Nanopowders obtained by modification of a cadmium sulfide powder in a citrate-ammonia solution of lead acetate have been studied by X-ray diffraction, electron microscopy, and thermal analysis. The type of crystal structure and composition of Cd-Pb-S nanopowders depend on the conditions of their synthesis. The thermoanalytical curves show a well-defined endotherm in the temperature range 284–321°C. The position of this endotherm depends on the duration of contact of a CdS powder with an aqueous solution of a lead salt. Heating nanopowders to 600°C in an argon flow leads to formation of oxygen-containing phases: lead sulfate and cadmium oxide.

Peculiarities of Microstructure and Composition of CdSe-PbSe Multilayered Films

The microstructure of end surfaces of CdSe-PbSe films obtained by layered (layer-by-layer) hydrochemical deposition has been studied using X-ray, scanning electron, and scanning probe microscopy. A method aimed at determining the number of layers, their thicknesses, and phase and chemical compositions using a pseudo-three-dimensional image in the ScanMaster package has been proposed.

Phase composition and some properties of titanium carbonitride-titanium nickelide alloys with Al2O3 nanoparticles

The phase formation in and the microstructure of titanium carbonitride-titanium nickelide alloys with aluminum oxide Al2O3 nanopowder additions are studied by X-ray diffraction, electron-microscopic, and electron-probe microanalyses. The phase interaction is characterized by the redistribution of nonmetallic elements and aluminum between refractory and binding phases with the formation of a nonstoichiometric titanium-aluminum (Ti,Al)(C,N) carbonitride and a titanium-aluminum nickelide. The number of forming phases and their compositions are controlled by the kinetic parameters of the process.

Effects of Vanadium and Niobium on the Phase Composition of Titanium-Carbonitride-Base Cermets with Titanium–Nickel Binder

The phase composition of V- or Nb-containing titanium-carbonitride-base cermets with a TiNi binder was investigated, and the content of the alloying metal in the refractory base of the alloys was determined. The alloys were found to consist of three phases: refractory phase, TiNi, and σ-Ni2V3 or NbzNi. The solubility of V in titanium carbonitride is very low, while that of Nb is fairly high and increases with Nb content. The phase composition of the cermets is shown to correlate with the Gibbs energies of formation of the constituent carbides.

Formation of solid solutions in the CdSe–PbSe system under the action of high pressures and temperatures

A method was proposed for producing solid solutions in the CdSe–PbSe systems, which is based on heat and high pressure treatment. X-ray powder diffraction analysis showed the formation of substitutional solid solutions CdxPb1–xSe with the NaCl structure, which contained 20, 40, 60, and 80 mol % cadmium selenide. The solid solutions were characterized by scanning electron microscopy, impedance spectroscopy, gas pycnometry, and Raman spectroscopy.

Effect of alloying on the phase composition of titanium carbonitride–titanium nickelide alloys

X-ray diffraction, electron microprobe analysis, electron microscopy, and chemical analysis are used to study the effect of alloying with zirconium, niobium, vanadium, and molybdenum on the phase composition of titanium carbonitride–titanium nickel cermets. It is shown that two-phase alloys containing alloyed titanium carbonitride and titanium nickelide can only be produced by alloying with zirconium. The addition of niobium, molybdenum, and vanadium leads to the formation of a third phase, namely, NbzNi, Mo(Ti,C), or V4Ni, in the alloy. A correlation between the phase composition of the alloys and the ratio of the energies of formation of titanium carbides and the carbides of alloying elements is found.

Hydrochemical Synthesis and Thermal Stability of Nanocrystalline Films and Precipitates of Copper(I) Selenide

Nanocrystalline films and precipitates of copper(I) selenide were prepared by chemical depositions from aqueous solutions at 333 K. Cubic structure of Cu2-xSe (space group Fm-3m) with crystal lattice constant 5.693 Å with inclusion of cubic phase of cuprous oxide Cu2O (space group 224) was revealed by X-ray diffraction of the precipitates. Freshly deposited films and precipitates were shown to consist of polyhedral crystallites with characteristic size of 50–400 and 80–500 nm, respectively. The found formula composition of hydrochemically deposited films and precipitates corresponds to compounds Cu1.54Se and Cu1.84Se, respectively. Elemental analysis data for Cu1.54Se films thermally treated in air atmosphere showed their stability to heating up to 220–230°C.