[en] Amorphous hydrogen-containing carbon films (C:H) are of considerable scientific and practical interest because of the unique combination of the physical properties: high hardness, low thermal conductivity with high electrical resistance, transparency in the infrared range. The determination of the radiation stability of these films is also important considering the fact that the ion beams are one of the tools of investigation of the hydrogen content, for example, by the methods MSVI or nuclear microanalysis. The determination of the main physical factors, determining the exit of hydrogen from the C:H films under the effect of radiation, was also the aim of these investigations. (author)

[en] X-ray-absorption fine structure (XAFS) and x-ray-diffraction (XRD) measurements of disordered alloys Au_xCu_1-x and Au_0.5Ag_0.5 prepared by melt spinning were performed. In the Au_0.5Ag_0.5 alloy, no significant local deviations of the atoms from the average fcc lattice were detected while in Au_xCu_1-x alloys, significant deviations of atoms from the average fcc lattice were found. Mean-square vibrations of the Cu-Cu distances revealed by the XAFS in Au_xCu_1-x alloys indicate the weakening of contact between Cu atoms in the dilute limit. Our computer simulation for Au_xCu_1-x clusters of 10⁵ atoms reproduces the main features of both the XAFS and XRD data

[en] Short communication

[en] CrAlC and CrAlSiC films have been obtained and investigated. Simultaneous sputtering of graphite and Cr₀₅Al₀₅ or Cr₀₃₅Al₀₅₅Si_{0 08} targets was used for films deposition. The structure of the films is amorphous-nanocrystalline. The doping of CrAlC films with silicon is accompanied by an increase in their crystallinity due to the formation of silicon carbide particles. Structural changes make CrAlSiC films harder with a higher resistance to plastic deformation. (paper)

[en] Single CrAlC, CrAlSiC and multilayer [CrAlC/a-C]_n, [CrAlSiC/a-C]_n coatings have been fabricated and investigated. Joint use of arc plasma source with Cr-Al(Si) cathode and pulsed arc plasma source with graphite cathode was applied to single coatings deposition. Diamond-like a-C layers alternate with CrAl(Si)C in multilayer coatings. The doping of CrAlC with silicon is accompanied by an increase in their crystallinity due to the formation of silicon carbide particles. Structural changes make CrAlSiC films harder with a low friction coefficient and a high resistance to plastic deformation. The multilayer coatings are crack resistant. (paper)

[en] There were investigated tribological properties of CrAlSiC coatings deposited by two techniques. In both techniques a plasma source of a cathode-arc discharge with Cr-Al-Si composite target served the source of Cr, Al, and Si atoms during coating deposition. A plasma source of a pulsed cathode-arc discharge with graphite cathode and a gas discharge device to generate a non-self-sustained discharge in argon-acetylene mixture have been used for generating carbon plasma in first and second techniques, correspondingly. First coating has a low coefficient of friction. Under frictional action, coating wears out uniformity without chipping. Second coating is less resistant to frictional action. (paper)

[en] X-ray-absorption fine-structure (XAFS) measurements of metallic glass Al_0.91La_0.09 and a crystalline phase Al₁₁La₃ formed by annealing of the glass were made at the La L₃ edge and analyzed by the splice method. The first-neighbor partial radial distribution functions about the La atoms for the crystal and glass were obtained at T=12 K demonstrating the difference between their local structures. The shortest La-Al distance (mean value 3.09±0.05 A) within the glass was distinctively smaller than within the crystal Al₁₁La₃ (3.21±0.05 A). This partial shortening of the La-Al bonds decreases the size mismatch between the La and Al atoms making the glass formation more favorable with anomalously low content of La during the quench. Monte Carlo simulations were performed for the Al-La glass and agreement with the XAFS result was obtained. copyright 1996 The American Physical Society

[en] A correlation between precise x-ray powder diffraction patterns and atomic size mismatch in disordered mixed crystals (alloys and ionic crystals) is observed. The anisotropy of the elastic moduli has been taken into account for evaluation of the strain energy density of the mixed crystals revealed in x-ray powder diffraction measurements. The precursor of the phase transformation for a quenched disordered Au-Cu alloy is identified. (author)

[en] XAFS data of metallic glass Al_0.91La_0.09 and a crystalline phase Al₁₁La₃ formed by annealing of the glass were measured at the La L₃ edge at T=12 K and analyzed using the radial distribution function method. The shortest La-Al distance appeared to be distinctively smaller within the glass than in the crystal. This difference decreases the disparity in size of La and Al in the alloy, allowing their mixing in the glassy state. ((orig.))

[en] Multilayer coatings [(TiC _x /Ti/a-C)+ta-C] _n with different composition of composite (TiC _x /Ti/a-C) layers are studied. The dependences of abrasive wear resistance and H ³/ E ² ratio ( H – hardness, E – elastic modulus) of multilayer coatings on the carbon content in the composite layer are determined. The phase composition of the (TiC _x /Ti/a-C) layer, the ratio of volume fractions of the phases and the volume fraction of interface component, interlayer adhesion and adhesion to the substrate of the multilayer coating have a synergistic effect on the wear resistance of the testing coatings. (paper)