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COATINGS

JPRS-UMS-92-003 16 March 1992

separated from the substrate. The crystalline lattice parameter was measured with an error of 0.01%. The studies performed established that when the electrolyte’s acidity is reduced from a pH of 2 to a pH of 6 (with a current density of 15 mA/cm²), the (110) growth texture of the study films remains unchanged. The concentration of their subtraction-type stacking faults increases, how-ever. Increasing the current from 5 to 70 mA/cm² (at a pH of 6) was found to facilitate an increase in the concentration of the specified defects and to cause the films’ texture to be restructured in the sequence (100), (210), (110). Adding saccharin to the electrolyte was found to result in the formation of a (111) texture and a reduction in the concentration of stacking faults. The mismatch between the film lattice parameter and that of the substrate, as well as the incorporation of impurities during crystal growth, were determined to be the main causes of the stacking faults discovered. These results were determined to be in good agreement with data published in two other Communications. The authors also proposed a formula for determining the probability of the appearance of stacking faults in electrodeposited coatings. Figures 2, table 1; references 14: 12 Russian, 2 Western.

Laws Governing the Growth of a Gold Film on a Benzene Substrate at 77 K

927D0067F Moscow POYERKHNOST: FIZIKA, KHIMIYA, MEKHANIKA in Russian No 12, Dec 91 (manuscript received 4 Apr 90; aft er revision 19 Dec 90) pp 98-104

[Article by V.L. Kamatsevich, B.S. Kaverin, G.A. Dom-rachev, and V.I. Zaykovskiy, Organometallic Chemistry Institute, USSR Academy of Sciences, Nizhniy Novgorod]

UDC 539.234:537.533.35

[Abstract] The authors of the study used the electron microscopy method to study the laws goveming the growth of gold films on benzene crystal substrates. The studies were conducted on a unit (described elsewhere) that madę it possible to produce a benzene film at 77 K on a copper substrate and to then condense heat-vaporized Au atoms onto it. The Au film formed on the benzene film-substrate complex was then extracted by using a carbon replica and analyzed by using a JEM-100CX high-resolution electron microscope. The laws goveming the formation and growth of Au films were studied as a function of the degree of coating of substrate m as determined by the total number of atoms deposited on 1 cm² of a fiat substrate parallel to the beam of atoms. First, the authors examined the condensation of Au onto molecularly smooth faces of crystals of a benzene substrate. The microscopy studies performed indicated that the said process occurs primarily by the mechanism of the union of the particles formed rather than by the formation of new nucleation centers. Two peaks were discovered in the size distribution of the said particles:

The first corresponded to close-to-spherical particles with a mean-weighted diameter of 3 nm, and the second corresponded to larger and longer particles with a mean-weighted diameter of 11 nm. The two types of particles were designated as rank 1 and rank 2 particles, respec-tively. The rank 2 particles were determined to be the result of the union of rank 1 particles, with the formation of bridges between the latter in some cases. The rank 1 particles were found to include individual tetrahedra with (111) planes truncated by peaks and morę complex particles (for example, with two Systems of bands corre-sponding to (111) planes) that were either parallel to one another or else disoriented. The rank 2 particles were determined to be polyparticles formed when tetrahedral fragments and multiple twinning particles (icosahedra and decahedra) join together. Ncxt, the authors tumed their attention to the condensation of Au films on molecularly rough faces of the crystals of the benzene substrate. The microscopy studies performed revealed that the particles formed when Au is condensed on the molecularly rough faces are morę isometric and morę disperse than the particles formed on molecularly smooth surfaces given identical substrate coatings. The moment of onset of formation of a continuous film is earlier, and there are no signs of surface decoration (such signs are observed in the case of the particles on the molecularly smooth surfaces). Analysis of the size distribution of the particles formed on the molecularly rough faces revealed the presence of a maximum in the rangę of particles smaller than 2 nm in size. This finding was taken as an indication that the ratę at which particles are generated exceeds the ratę at which their shape changes owing to interaction in the ensemble of islands. Figures 4; references 12: 8 Russian, 4 Western.

The Formation Mechanism of Films Produced by Reactive Ion-PIasma Deposition

927D0067C Moscow POVERKHNOST: FIZIKA, KHIMIYA, MEKHANIKA in Russian No 12, Dec 91 (manuscript received 20 Aug 90; aft er remion 24 Jan 91) pp 24-28

[Article by A.N. Pilyankevich (deceased), V.Yu. Kulik-ovskiy, and L.R. Shaginyan; Materials Science Problems Institute, Ukrainę Academy of Sciences, KJev]

UDC 539.216:661.55:669.29:621.793.7

[Abstract] The authors of the study worked to deve!op a methodology that would make it possible to estimate the contribution of chemically active gas particles to the process of synthesis of titanium nitride films. For the said studies, titanium nitride films were produced by using a planar magnetron system with an annular magnet and disk target with a constant current. Two sputtering techniques were used. In one, a titanium nitride disk produced by powder metallurgy techniques and sput-tered in argon served as the target. In the other method, a titanium target was sputtered in a nitrogen-argon atmosphere. The targets were about 50 mm in diameter,