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2108. The influence of adsorption of lanthanides on Ir surface and the influence of oxygen on the concentration dependence of work function of the IrYb film system.
Classified abstracts 2 1 0 1 - 2 2 4 8 Classified abstracts on this page 2 1 0 1 - 2 1 1 1
Editor's note
The label immediately following the title of each item denotes country or origin of publication, and that at the end of each abstract indicates country of origin of work (where known).
I. G e n e r a l v a c u u m s c i e n c e and e n g i n e e r i n g 11. GASES AND SOLIDS 11 2101. Ion plating--a new process in vacuum coating. (Germany) This article reviews the process of ion plating which assists the well known vacuum coating process by means of ions. After considering the elementary processes and condensation conditions prevailing in ion plating the physical properties of layers produced by ion plating are derived with respect to the applicability of such layers. Decisive for the effectiveness of the process is the energetic activation. The main parameters and modes of operation for ion plating are discussed, also solutions for the design of the respective practical devices are given. (East Germany) Von S Schiller et al, Vakuum-Tech, 25 (3), 1976, 65-72 (in German). 11 2102. Peak shifts in thermal desorption experiments due to vacuum time constants--a generalized solution. (GB) The shift in the maximum (Tm) of the pressure transient during a thermal desorption experiment from the maximum (Tp) of the sample desorption rate due to the influence of the vacuum time constant r is considered. It is shown that AT/AW, where AT : T m -- Tp and AW is the full width at half height of the sample desorption rate, is determined by the quantity flr/A W where/3 is the temperature sweep rate. A general solution of A T / A W as a function of flr/AW is given for 1 0 - 3 < ~ r / A W < 103 for both first and second order desorption transients. In addition an optimization criterion for thermal desorption experiments is described and the implications of this criterion considered. It is found in particular that the simultaneous requirements of negligibly low distortion with maximum measured signal amplitude are satisfied for flT/A 14/~ 0.I for an elementary first or second order desorption transient. (USA) D Edwards Jr, Vacuum, 26 (3), 1976, 91-95. 11 2103. Range profiles of 6-16-keV ions implanted in metal oxides. (USA) The range profiles of 6-16 keV hydrogen ions implanted in the amorphous metal oxides A1203, Nb2Os, Ta205 have been measured. The profiles were determined by use of the nuclear reaction xH( ~gF, ~v) 160. Good agreement with theoretical predictions is observed for the most probable ranges, while the widths of the experimental distributions are substantially larger than theoretically calculated for AI2Oa and Nb2Os. (Denmark) J Bottiger et aI, JApplPhys, 47 (4), 1976, 1672-1675. 11 2104. Angular deformations of energy spectra of Cs + ions at their scattering by the surface of single crystal molybdenum. (USSR) Energy spectra at scattering of 700 eV Cs + ions at an angle of 92 ° by single crystal molybdenum held at a temperature of 1800 K are investigated. Experimental results are discussed. Yu A Agadzhanov et al, Fiz Tverd Tela, 17 (6), 1975, 1810-1812 (in
Russian). 11 2105. Adsorption and condensation of silver on tungsten. (USSR) Using a magnetic sector mass spectrometer, the dependence of residence time and activation energy of desorption of silver atoms on concentration of silver atoms adsorbed on tungsten surface is investigated at a residual pressure of 5 × 10 -9 torr. N I Ionov and M A Mittsiev, Fiz Tverd Tela, 17 (6), 1975, 1607-1612
(in Russian). 11 2106. Nature of photoeonduetivity of NiO, Cr2Oa and Fe20 a. (USSR) Using a static capacitor, the photoelectrical polarization of NiO, Cr2Oa and Fe2Oa is investigated in a vacuum chamber evacuated to
2 × 10 -~ torr. It is found that the effect of photoelectrical polarization is observed in the examined oxides only at presence of chemisorbed oxygen on their surface. Ya L Kharif et al, Fiz Tverd Tela, 17 (4), 1975, 987-990 (in Russian). 11 2107. On the influence of conditions of formation on adsorption properties of layers of condensed gases. A model of sorbents. (USSR) The influence of the deposition rate, substrate temperature, predeposition temperature, substrate material and concentration of impurities on the adsorption properties of layers of condensed gases is considered. The adsorption isotherms of hydrogen on layers of CO2 at 20.4 K are measured for various deposition rates and concentrations of impurities. It is found that the presence of low amounts of impurities only slightly influences the adsorption properties but decreases the sensitivity to the deposition rate. The desorption isotherm of helium on the CO2 layer, prepared in conditions of cryotrapping at a temperature of 20 K and helium partial pressure of 10 -3 torr is presented. The problem of cryotrapping-adsorption effect at simultaneous deposition of sorbent and sorbate is discussed. A model of the sorbent consisting of layers of condensed gases is presented. V B Yuferov, Zh Tekh Fiz, 45 (3), 1975, 609~515 (in Russian). 11 2108. The influence of adsorption of lanthanides on Ir surface and the influence of oxygen on the concentration dependence of work function of the lr-Yb film system. (USSR) Using the method of modulation of temperature, kinetic characteristics of thermal desorption of Yb atoms from the surface of textured iridium filament oriented in the (111 ) direction are investigated. The desorption heat of Yb atoms is found to be 4.8 -A- 0.2 eV and that of Yb + ions 5.1 eV. Simultaneously the dependences of work function on the coverage degree of lanthanum and ytterbium on iridium are measured. The residual gas pressure during experiments was less than 5 × 10- 8 torr. It is found that La films on lr surface possess a diffusion character at 1800 K and coverage degree less than unity. The influence of oxygen partial pressure of 2 × 10 -6 torr on the concentration dependence of work function is measured for the system Ir-La. N I Ionov and B K Medvedev, Fiz Tverd Tela, 17 (3), 1975, 800-805
(in Russian). 11 2109. Determination of desurption energy. (Czechoslovakia) The values of partial pressures of gases or their surface concentrations, determined by mass spectrometry or desorption spectrometry, are usually used for calculation of the desorption energy. It is mathematically shown that the value of desorption energy can be determined from the graphical dependence of desorption rate on temperature. This dependence can be obtained with the aid of measurement of the total pressure. J Kalu~ay, Acta Fac Rerum Natur Univ Comen Phys, No 13, 1973, 1-8 in Slovak). 11 2110. Depth distribution and annealing of defects in silicon implanted with lithium ions. (USSR) Using the method of elastic scattering of 1.8 MeV He4ions, the depth distribution and annealing of defects produced in silicon by implantation of 80 keV lithium ions at a dose of 8 × 10 t6 ion/cm 2 and current density of 3 p.A/cm2 are investigated. N A Skakun et al, Fiz Tverd Tela, 17 (3), 1975, 927-929 (in Russian). 11 2111. Profiles of radiation defects and implanted boron in silicon. (USSR) Using the method of elastically scattered 1.8 MeV helium ions, the profiles of radiation defects and implanted boron ions in silicon are 487
Editor's note
The label immediately following the title of each item denotes country or origin of publication, and that at the end of each abstract indicates country of origin of work (where known).
I. G e n e r a l v a c u u m s c i e n c e and e n g i n e e r i n g 11. GASES AND SOLIDS 11 2101. Ion plating--a new process in vacuum coating. (Germany) This article reviews the process of ion plating which assists the well known vacuum coating process by means of ions. After considering the elementary processes and condensation conditions prevailing in ion plating the physical properties of layers produced by ion plating are derived with respect to the applicability of such layers. Decisive for the effectiveness of the process is the energetic activation. The main parameters and modes of operation for ion plating are discussed, also solutions for the design of the respective practical devices are given. (East Germany) Von S Schiller et al, Vakuum-Tech, 25 (3), 1976, 65-72 (in German). 11 2102. Peak shifts in thermal desorption experiments due to vacuum time constants--a generalized solution. (GB) The shift in the maximum (Tm) of the pressure transient during a thermal desorption experiment from the maximum (Tp) of the sample desorption rate due to the influence of the vacuum time constant r is considered. It is shown that AT/AW, where AT : T m -- Tp and AW is the full width at half height of the sample desorption rate, is determined by the quantity flr/A W where/3 is the temperature sweep rate. A general solution of A T / A W as a function of flr/AW is given for 1 0 - 3 < ~ r / A W < 103 for both first and second order desorption transients. In addition an optimization criterion for thermal desorption experiments is described and the implications of this criterion considered. It is found in particular that the simultaneous requirements of negligibly low distortion with maximum measured signal amplitude are satisfied for flT/A 14/~ 0.I for an elementary first or second order desorption transient. (USA) D Edwards Jr, Vacuum, 26 (3), 1976, 91-95. 11 2103. Range profiles of 6-16-keV ions implanted in metal oxides. (USA) The range profiles of 6-16 keV hydrogen ions implanted in the amorphous metal oxides A1203, Nb2Os, Ta205 have been measured. The profiles were determined by use of the nuclear reaction xH( ~gF, ~v) 160. Good agreement with theoretical predictions is observed for the most probable ranges, while the widths of the experimental distributions are substantially larger than theoretically calculated for AI2Oa and Nb2Os. (Denmark) J Bottiger et aI, JApplPhys, 47 (4), 1976, 1672-1675. 11 2104. Angular deformations of energy spectra of Cs + ions at their scattering by the surface of single crystal molybdenum. (USSR) Energy spectra at scattering of 700 eV Cs + ions at an angle of 92 ° by single crystal molybdenum held at a temperature of 1800 K are investigated. Experimental results are discussed. Yu A Agadzhanov et al, Fiz Tverd Tela, 17 (6), 1975, 1810-1812 (in
Russian). 11 2105. Adsorption and condensation of silver on tungsten. (USSR) Using a magnetic sector mass spectrometer, the dependence of residence time and activation energy of desorption of silver atoms on concentration of silver atoms adsorbed on tungsten surface is investigated at a residual pressure of 5 × 10 -9 torr. N I Ionov and M A Mittsiev, Fiz Tverd Tela, 17 (6), 1975, 1607-1612
(in Russian). 11 2106. Nature of photoeonduetivity of NiO, Cr2Oa and Fe20 a. (USSR) Using a static capacitor, the photoelectrical polarization of NiO, Cr2Oa and Fe2Oa is investigated in a vacuum chamber evacuated to
2 × 10 -~ torr. It is found that the effect of photoelectrical polarization is observed in the examined oxides only at presence of chemisorbed oxygen on their surface. Ya L Kharif et al, Fiz Tverd Tela, 17 (4), 1975, 987-990 (in Russian). 11 2107. On the influence of conditions of formation on adsorption properties of layers of condensed gases. A model of sorbents. (USSR) The influence of the deposition rate, substrate temperature, predeposition temperature, substrate material and concentration of impurities on the adsorption properties of layers of condensed gases is considered. The adsorption isotherms of hydrogen on layers of CO2 at 20.4 K are measured for various deposition rates and concentrations of impurities. It is found that the presence of low amounts of impurities only slightly influences the adsorption properties but decreases the sensitivity to the deposition rate. The desorption isotherm of helium on the CO2 layer, prepared in conditions of cryotrapping at a temperature of 20 K and helium partial pressure of 10 -3 torr is presented. The problem of cryotrapping-adsorption effect at simultaneous deposition of sorbent and sorbate is discussed. A model of the sorbent consisting of layers of condensed gases is presented. V B Yuferov, Zh Tekh Fiz, 45 (3), 1975, 609~515 (in Russian). 11 2108. The influence of adsorption of lanthanides on Ir surface and the influence of oxygen on the concentration dependence of work function of the lr-Yb film system. (USSR) Using the method of modulation of temperature, kinetic characteristics of thermal desorption of Yb atoms from the surface of textured iridium filament oriented in the (111 ) direction are investigated. The desorption heat of Yb atoms is found to be 4.8 -A- 0.2 eV and that of Yb + ions 5.1 eV. Simultaneously the dependences of work function on the coverage degree of lanthanum and ytterbium on iridium are measured. The residual gas pressure during experiments was less than 5 × 10- 8 torr. It is found that La films on lr surface possess a diffusion character at 1800 K and coverage degree less than unity. The influence of oxygen partial pressure of 2 × 10 -6 torr on the concentration dependence of work function is measured for the system Ir-La. N I Ionov and B K Medvedev, Fiz Tverd Tela, 17 (3), 1975, 800-805
(in Russian). 11 2109. Determination of desurption energy. (Czechoslovakia) The values of partial pressures of gases or their surface concentrations, determined by mass spectrometry or desorption spectrometry, are usually used for calculation of the desorption energy. It is mathematically shown that the value of desorption energy can be determined from the graphical dependence of desorption rate on temperature. This dependence can be obtained with the aid of measurement of the total pressure. J Kalu~ay, Acta Fac Rerum Natur Univ Comen Phys, No 13, 1973, 1-8 in Slovak). 11 2110. Depth distribution and annealing of defects in silicon implanted with lithium ions. (USSR) Using the method of elastic scattering of 1.8 MeV He4ions, the depth distribution and annealing of defects produced in silicon by implantation of 80 keV lithium ions at a dose of 8 × 10 t6 ion/cm 2 and current density of 3 p.A/cm2 are investigated. N A Skakun et al, Fiz Tverd Tela, 17 (3), 1975, 927-929 (in Russian). 11 2111. Profiles of radiation defects and implanted boron in silicon. (USSR) Using the method of elastically scattered 1.8 MeV helium ions, the profiles of radiation defects and implanted boron ions in silicon are 487