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Investigation of bombardment of glass by ions from a glow discharge
Classified abstracts 425-439
model for the energy levels allowing an interpretation of the experimental results is suggested. (France). M Zouaghi et al, Phys Srur Sol (a), 11 (2), June 1972,449-460. 33:30 425. Investigation of bombardment of glass by ions from a glow discharge. (USSR) In connection with the dependence of the structure of metal films, prepared by vacuum evaporation and condensation, on the state of the substrate surface, the method of cleaning the substrate surface by bombardment with positive ions from a glow discharge is investigated. The increase in substrate temperature during glow-discharge treatment is determined and the substrate surface after bombardment is examined by electron microscopy. V M Egorov, Trudy Sev-zap Zaoch Poiitekh Znst, No 14, 1971, 91-93 (in Russian).
37 433. The growth of (3-copper phthalocyanine single crystals by evag oration. (Germany) An apparatus for growth from the vapour phase of large-size single crystals of the B-modification of copper phthalocyanine is described. Crystallization is performed in a flow of nitrogen at 10 torr in a quartz vessel. The apparatus is initially cleaned and degassed to a pressure of 10m5 torr. C Hamman, Krist Technik, 6 (4), 1971, 491-498. 37 434. Heat and entropy of melting of ZnTe. (USSR)
Heat and entropy of melting of semiconducting ZnTe are determined using the method of differential-thermal analysis in a Stepanov vessel evacuated to 1 x 10e4 torr. V N Vigdorovich et al, Neorg Mater, 8 (4), April 1972, 753-754 (in Russian). 37
37. METALLURGY, INORGANIC ANALYTICAL CHEMISTRY
435. Thermal decomposition
CHEMISTRY, 37
426. Decoration
effects in germanium. (Bulgaria) Results of electron-microscopic investigations of single and polycrystalline Ge surfaces, thermally treated in vacuum and decorated with gold, are presented. Data on the crystallographic and geometrical surface elements were obtained. N K Pashov, Dokl Bolg Akad Nuuk, 24 (8), 1971, 1015-1017.
427. Radiation-induced cium fluoride. (USSR)
changes
in the electrical
conductivity
37 of cal-
Electrical conductivity of CaF, crystals is measured at 10m3 torr in the temperature range 30 to 500°C in dependence on the irradiation dose of protons with energy of 4.5 MeV. Experimental results are discussed. E K Zavadovskaya et al, Izv VUZ Fiz, No 5, 1972, 167-168 (in Russian). 428. Electrical conductivity of microlite at elevated temperatures reactor radiation field. (USSR)
37 in a
Electrical conductivity of microlite is investigated in the vertical canal of a reactor at pressure of 10m3 torr, thermal neutron flux density of 1.3 x lOI neutron/cm2 s, and temperatures of 100 to 800°C. Experimental results are discussed. U G Gulyamov, Izv AN UzSSR Ser Fir Mat Nauk, No 1, 1972, 8386 (in Russian). 429. The thermally active nature of plastic crystals. (Germany)
37 of a-Al,O,
deformation
The dependence of the thermally active parameters on temperature and shear stress was studied for a-Al,O, crystals in vacuum of 1O-5 torr. A mechanism of plastic deformation in the temperature range from 1650 to 2OOOC is suggested. (USSR). V G Govorkov et al, Phys Stat Sol (a), 11(2), June 1972,411-420. 430. The substructure of diffusion zone in copper-alpha couple. (Czechoslovakia)
37 brass diffusion
The diffusion zone of a three-layer sample annealed in argon ambient and in vacuum at 10e3 torr, was studied by electron microscopy, x-ray diffraction and light microscopy. R Fiedler et al, Czech J Phys, B 22 (5), 1972, 405-412.
of boron arsenide. (USSR)
Thermal stability of BAs in vacuum is investigated using the gravimetric method. Analysis of the decomposition products was performed by mass spectrometry of gas phase. It is found that thermal decomposition of BAs at 10v6 torr begins at 580°C and it is connected with release of arsenic and formation of boron subarsenide. This process is complete at 1060°C. A F Radchenko et al, Neorg Mater, 8 (4), April 1972, 767-768 (in Russian). 37 436. Solid solutions in the system ZrO,-Yb,O,
(USSR) Kinetics of formation of solid solutions and ZrO,-YzO,-YbzO, is investigated. after heating in air and in a vacuum determined. A K Kuznetsov et al, Neorg Mater, 8
and Zr02-Ya03-Yb*O,.
in the systems ZrO,-Yb,O, Properties of these materials furnace at 1 x 10e4 torr are (4), April
1972, 749-752
(in
Russian). 37 437. The formation of very thin oxide films on metals: contact potential measurements during the oxidation of different crystallographic faces of copper. (USA)
High purity copper single crystals were used in an ultrahigh vacuum system (lo-l0 torr) and cleaned by argon ion bombardment. Surface damage was removed by annealing at temperatures up to 450°C by electron bombardment. A high purity gold polycrystal was similarly treated. A model is proposed for the low temperature oxidation of copper. The predictions of the model are compared with experimental observations of the change in contact potential difference when clean (100). (110) and (111) copper surfaces are oxidized at room temperature. A value of 0.7510.03 eV for the activation energy for formation of a copper ion vacancy is derived from the process of fitting experiment to theory. The interpretation of the observed changes in contact potential difference is made in terms of surface states located at the metal-oxide interface and at the gas-oxide interface. E Boggle, J Chem Phys, 57 (1 l), 1st Dee 1972, 47384742. 31 438. Vapour pressure and heat of vapourization
of cobalt. (USA)
A Knudsen cell assembly and a high-resolution Herzog-Mattauch type of mass spectrometer were used. The temperature used was 1519-1926°K. The derived third-law heat of vapourization of cobalt is AH:_= 101.0_+0.6 kcahmole. Plausible exnlanations are given for the widely differing values of vapour pressures and heais of sublimation as compared to values quoted in the literature. It is shown that the evaporation coefficient for cobalt is essentially unity rather than 3 x lo-* and that the electron impact ionization crosssection for cobalt is o(Co)=4.4&1 x lo-l6 cm2 for 50 eV electrons. F M Wachi and D E Gilmartin. J Chem Phys, 57 (1 l), 1st Dee 1972, 4713-4716. 37 439. Growth of corundum crystals. (USSR) Influence of various factors on growth of thread-like crystals of corundum in the oxidation of metallic aluminium is investigated and possible chemical reactions are considered. Influence of water vapour at partial pressures of 10e2 to 1 torr, contained in hydrogen or argon ambient, on the formation of corundum is studied, V S Postnikov et al, Neorg Mater, 8 (4), April 1972, 714-718 (in I””
37 431. Investigation of changes occurring in diamonds during heating. (USSR) Changes in diamonds on heating in a vacuum of 8 x 10e5 torr, H,, Ar and CO/CO2 ambients are investigated using x-ray methods. A V Belyankina et al, Synthetic Diamonds, Scient-Product Coll, No 1, Kiev 1972, 20-22 (in Russian). 432. Dehydration
of some single and co-deposited
hydrates
37 of oxides.
(USSR) Using the method of complex thermal analysis with recording of outgassing, the dehydration of hydrated oxides of Al, Fe, Cr and Si is investigated at pressures from atmospheric to 5 torr. The dehydration heats are determined. I A Leonteva Russian).
et al, Neorg
Mater,
8 (4), April
1972,
787-788
(in
Russian). 153
model for the energy levels allowing an interpretation of the experimental results is suggested. (France). M Zouaghi et al, Phys Srur Sol (a), 11 (2), June 1972,449-460. 33:30 425. Investigation of bombardment of glass by ions from a glow discharge. (USSR) In connection with the dependence of the structure of metal films, prepared by vacuum evaporation and condensation, on the state of the substrate surface, the method of cleaning the substrate surface by bombardment with positive ions from a glow discharge is investigated. The increase in substrate temperature during glow-discharge treatment is determined and the substrate surface after bombardment is examined by electron microscopy. V M Egorov, Trudy Sev-zap Zaoch Poiitekh Znst, No 14, 1971, 91-93 (in Russian).
37 433. The growth of (3-copper phthalocyanine single crystals by evag oration. (Germany) An apparatus for growth from the vapour phase of large-size single crystals of the B-modification of copper phthalocyanine is described. Crystallization is performed in a flow of nitrogen at 10 torr in a quartz vessel. The apparatus is initially cleaned and degassed to a pressure of 10m5 torr. C Hamman, Krist Technik, 6 (4), 1971, 491-498. 37 434. Heat and entropy of melting of ZnTe. (USSR)
Heat and entropy of melting of semiconducting ZnTe are determined using the method of differential-thermal analysis in a Stepanov vessel evacuated to 1 x 10e4 torr. V N Vigdorovich et al, Neorg Mater, 8 (4), April 1972, 753-754 (in Russian). 37
37. METALLURGY, INORGANIC ANALYTICAL CHEMISTRY
435. Thermal decomposition
CHEMISTRY, 37
426. Decoration
effects in germanium. (Bulgaria) Results of electron-microscopic investigations of single and polycrystalline Ge surfaces, thermally treated in vacuum and decorated with gold, are presented. Data on the crystallographic and geometrical surface elements were obtained. N K Pashov, Dokl Bolg Akad Nuuk, 24 (8), 1971, 1015-1017.
427. Radiation-induced cium fluoride. (USSR)
changes
in the electrical
conductivity
37 of cal-
Electrical conductivity of CaF, crystals is measured at 10m3 torr in the temperature range 30 to 500°C in dependence on the irradiation dose of protons with energy of 4.5 MeV. Experimental results are discussed. E K Zavadovskaya et al, Izv VUZ Fiz, No 5, 1972, 167-168 (in Russian). 428. Electrical conductivity of microlite at elevated temperatures reactor radiation field. (USSR)
37 in a
Electrical conductivity of microlite is investigated in the vertical canal of a reactor at pressure of 10m3 torr, thermal neutron flux density of 1.3 x lOI neutron/cm2 s, and temperatures of 100 to 800°C. Experimental results are discussed. U G Gulyamov, Izv AN UzSSR Ser Fir Mat Nauk, No 1, 1972, 8386 (in Russian). 429. The thermally active nature of plastic crystals. (Germany)
37 of a-Al,O,
deformation
The dependence of the thermally active parameters on temperature and shear stress was studied for a-Al,O, crystals in vacuum of 1O-5 torr. A mechanism of plastic deformation in the temperature range from 1650 to 2OOOC is suggested. (USSR). V G Govorkov et al, Phys Stat Sol (a), 11(2), June 1972,411-420. 430. The substructure of diffusion zone in copper-alpha couple. (Czechoslovakia)
37 brass diffusion
The diffusion zone of a three-layer sample annealed in argon ambient and in vacuum at 10e3 torr, was studied by electron microscopy, x-ray diffraction and light microscopy. R Fiedler et al, Czech J Phys, B 22 (5), 1972, 405-412.
of boron arsenide. (USSR)
Thermal stability of BAs in vacuum is investigated using the gravimetric method. Analysis of the decomposition products was performed by mass spectrometry of gas phase. It is found that thermal decomposition of BAs at 10v6 torr begins at 580°C and it is connected with release of arsenic and formation of boron subarsenide. This process is complete at 1060°C. A F Radchenko et al, Neorg Mater, 8 (4), April 1972, 767-768 (in Russian). 37 436. Solid solutions in the system ZrO,-Yb,O,
(USSR) Kinetics of formation of solid solutions and ZrO,-YzO,-YbzO, is investigated. after heating in air and in a vacuum determined. A K Kuznetsov et al, Neorg Mater, 8
and Zr02-Ya03-Yb*O,.
in the systems ZrO,-Yb,O, Properties of these materials furnace at 1 x 10e4 torr are (4), April
1972, 749-752
(in
Russian). 37 437. The formation of very thin oxide films on metals: contact potential measurements during the oxidation of different crystallographic faces of copper. (USA)
High purity copper single crystals were used in an ultrahigh vacuum system (lo-l0 torr) and cleaned by argon ion bombardment. Surface damage was removed by annealing at temperatures up to 450°C by electron bombardment. A high purity gold polycrystal was similarly treated. A model is proposed for the low temperature oxidation of copper. The predictions of the model are compared with experimental observations of the change in contact potential difference when clean (100). (110) and (111) copper surfaces are oxidized at room temperature. A value of 0.7510.03 eV for the activation energy for formation of a copper ion vacancy is derived from the process of fitting experiment to theory. The interpretation of the observed changes in contact potential difference is made in terms of surface states located at the metal-oxide interface and at the gas-oxide interface. E Boggle, J Chem Phys, 57 (1 l), 1st Dee 1972, 47384742. 31 438. Vapour pressure and heat of vapourization
of cobalt. (USA)
A Knudsen cell assembly and a high-resolution Herzog-Mattauch type of mass spectrometer were used. The temperature used was 1519-1926°K. The derived third-law heat of vapourization of cobalt is AH:_= 101.0_+0.6 kcahmole. Plausible exnlanations are given for the widely differing values of vapour pressures and heais of sublimation as compared to values quoted in the literature. It is shown that the evaporation coefficient for cobalt is essentially unity rather than 3 x lo-* and that the electron impact ionization crosssection for cobalt is o(Co)=4.4&1 x lo-l6 cm2 for 50 eV electrons. F M Wachi and D E Gilmartin. J Chem Phys, 57 (1 l), 1st Dee 1972, 4713-4716. 37 439. Growth of corundum crystals. (USSR) Influence of various factors on growth of thread-like crystals of corundum in the oxidation of metallic aluminium is investigated and possible chemical reactions are considered. Influence of water vapour at partial pressures of 10e2 to 1 torr, contained in hydrogen or argon ambient, on the formation of corundum is studied, V S Postnikov et al, Neorg Mater, 8 (4), April 1972, 714-718 (in I””
37 431. Investigation of changes occurring in diamonds during heating. (USSR) Changes in diamonds on heating in a vacuum of 8 x 10e5 torr, H,, Ar and CO/CO2 ambients are investigated using x-ray methods. A V Belyankina et al, Synthetic Diamonds, Scient-Product Coll, No 1, Kiev 1972, 20-22 (in Russian). 432. Dehydration
of some single and co-deposited
hydrates
37 of oxides.
(USSR) Using the method of complex thermal analysis with recording of outgassing, the dehydration of hydrated oxides of Al, Fe, Cr and Si is investigated at pressures from atmospheric to 5 torr. The dehydration heats are determined. I A Leonteva Russian).
et al, Neorg
Mater,
8 (4), April
1972,
787-788
(in
Russian). 153