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An oxide of tervalent nickel
Classified Abstracts 77--84
49
Vacuum Applications 30.
E v a p o r a t i o n and S p u t t e r i n g 30
77. Cadmium coating under vacuum curbs hydrogen enbrittlement. Anon., 1ton Age, 188 (19), 9 Nov. 1961, 120-121. 30 : 37 78. An oxide of tervalent nickel. United States. Electron diffraction studies of films of nickel deposited on the cleavage face of hot rock-salt by e~aporation from a pure nickel filament at 10 -~ to 10 -~ Tort produced rings indicating the existence of an oxide having a hexagonal structure in addition to NiO as contaminants in the nickel film. The authors suggest that the unknown oxide may be NizOa because of the similarity of the crystal structure to Co203. B. B. D .
P. S. Aggarwal and A. Goswami, J. Phys. Chem., 65 ~.11), Nov. 1961, 2105. 30 79. Some aspects of research on thin solid films. Great Britain. A review article which surveys the applications of vacuum-deposited thin films in instruments, gives a brief history of research into methods of deposition and film properties, and concludes with an account of some of the current research. The appearance, during the last 10 years, of a number of thin film applications in electronics, additional to older applications in optics, is noted. Microminiature capacitors and resistors are produced by combinations of evaporation and sputtering, while complete oscillators, binary circuits, and other such elements are made (except for the active devices) by successive deposition of conducting and dielectric materials through copper masks. Computer memory devices using small area magnetic films having square-loop characteristics, and others using films of superconducting elements are mentioned, as are a variety of thin-film radiation detectors, image conxerters, etc. Some of the early research into the mechanism of film growth is referred to, including the theories of Frenkel, Pound, and others about the occurrence of a critical temperature for condensation, the growth of nuclei, etc. A number of examples are given of current research work, the importance of ultra-high vacua being stressed. Photographs show the growth of nuclei as observed in the electron microscope and in the field emission microscope. both of which have been used in recent ~ork. Very little fundamental research is said to have been done on the mechmff~.m of adhesion of film to substrate, which involves the binding energy, and some recent methods which have been used to measure this latter are discussed, one of which involves an attempt to con~ert the " s c r a t c h t e s t " for adhesion into a quantitative measurement of the binding energy. Another interesting experiment im olved the measurement of the differential temperature rise of two parts of a thin aluminium oxide substrate (one part being coated with bismuth oxide) when gold condensed on to i t ; the thermocouple was in thin film form, deposited on the back of the substrate. It is commented that the process of solidification from a molecular beam is different from that of solidification from the molten state and that the growth of a film to appreciable thickness is as deserving of study as the initial stages of growth. In technical applications. the ability to produce films having structure similar to that of the solid state would usually be an advantage. 44 references. M . D . A.
K. M. Greenland, J. Sci. Instrum., 38 (I), Jan. 1961, 1-11. 30 : 45 80. Welding of conducting electrodes to thin metallic films. S. Dembicka-Jellonkowa, J. ScL lnstrum., 38 (2), Feb. 1961, 62.
30 : 49 81. A simple method of monitoring the rate of deposition of a conducting film in a vacuum chamber. K. Feldmesser, J. Sci. Instrun,., 38 ~3), March 1961, 104. 30:19
Fiber optics.
IX. Waveguide effects.
See Abstr. No. 40.
30:19 Transmission properties of optical fibers. See Abstr. No. 41.
Multiple-~avelength multiple-beam interferometric on fiat surfaces. See Abstr. No. 42.
30:19 observation
30:19 Infrared transmittance of crystalline yttrium oxide and related compounds. See Abstr. No. 43. 30:19 Infrared transmittance of strontium titanate from room temperature to --180:C. See Abstr. No. 44.
31.
E v a c u a t i o n and S e a l i n g
31:44 82. Simple method of mounting and stretching thin gauze, sheet or foil f o r use in an electron tube_-. P. A. Einstein, J. Sci. Instrum., 37 (2), Feb. 1960, 67.
32.
Nucleonics
32 83. Isotopic analysis of boron in boron trifluoride by mass spectrometry, and measurement of natural boron 10 concentration. Great Britain. A conventional mass spectrometer is used for precise measurements of the isotope ratios of boron in boron trifluoride samples ~ith widely differing concentrations of boron 10. " Memory " effects caused by the adsorption of boron trifluoride on to the surfaces of the inlet system have been investigated, and it is found that these can be reduced to a workable level by careful design of the inlet system ; the construction of a glass leak for the inlet system is described. The preparation of standard samples is discussed. (Author, modified) P. G. Bentley, J. Sci. Instrum., 37 (9), Sept. 1960, 323-328.
84. Ratiometer for low-current mass spectrometry. Great Britain. This paper describes a technique for measuring isotopic abundance ratios with only a single ion beam and detector. The magnetic field of the conventional spectrometer is adjusted to bring the desired part of the spectrum on to the exit slit of the instrument, while the exact mass of ion passing through the slit is selected by a transverse electric field between two plates reminiscent of the deflexion plates of a cathode-ray tube. To compare the abundance of t ~ o isotopes, the transverse field is switched between two adjustable values so that ions of the required two mass numbers pass alternately through the slit to the detector. The output from each detector is fed to a separate scalar. After a convenient number of complete switching cycles, the indications of the two scalars are proportional to the relative abundances of the two isotopes. A novel form of detector, first introduced by Schutze and Berhardt, is used.
49
Vacuum Applications 30.
E v a p o r a t i o n and S p u t t e r i n g 30
77. Cadmium coating under vacuum curbs hydrogen enbrittlement. Anon., 1ton Age, 188 (19), 9 Nov. 1961, 120-121. 30 : 37 78. An oxide of tervalent nickel. United States. Electron diffraction studies of films of nickel deposited on the cleavage face of hot rock-salt by e~aporation from a pure nickel filament at 10 -~ to 10 -~ Tort produced rings indicating the existence of an oxide having a hexagonal structure in addition to NiO as contaminants in the nickel film. The authors suggest that the unknown oxide may be NizOa because of the similarity of the crystal structure to Co203. B. B. D .
P. S. Aggarwal and A. Goswami, J. Phys. Chem., 65 ~.11), Nov. 1961, 2105. 30 79. Some aspects of research on thin solid films. Great Britain. A review article which surveys the applications of vacuum-deposited thin films in instruments, gives a brief history of research into methods of deposition and film properties, and concludes with an account of some of the current research. The appearance, during the last 10 years, of a number of thin film applications in electronics, additional to older applications in optics, is noted. Microminiature capacitors and resistors are produced by combinations of evaporation and sputtering, while complete oscillators, binary circuits, and other such elements are made (except for the active devices) by successive deposition of conducting and dielectric materials through copper masks. Computer memory devices using small area magnetic films having square-loop characteristics, and others using films of superconducting elements are mentioned, as are a variety of thin-film radiation detectors, image conxerters, etc. Some of the early research into the mechanism of film growth is referred to, including the theories of Frenkel, Pound, and others about the occurrence of a critical temperature for condensation, the growth of nuclei, etc. A number of examples are given of current research work, the importance of ultra-high vacua being stressed. Photographs show the growth of nuclei as observed in the electron microscope and in the field emission microscope. both of which have been used in recent ~ork. Very little fundamental research is said to have been done on the mechmff~.m of adhesion of film to substrate, which involves the binding energy, and some recent methods which have been used to measure this latter are discussed, one of which involves an attempt to con~ert the " s c r a t c h t e s t " for adhesion into a quantitative measurement of the binding energy. Another interesting experiment im olved the measurement of the differential temperature rise of two parts of a thin aluminium oxide substrate (one part being coated with bismuth oxide) when gold condensed on to i t ; the thermocouple was in thin film form, deposited on the back of the substrate. It is commented that the process of solidification from a molecular beam is different from that of solidification from the molten state and that the growth of a film to appreciable thickness is as deserving of study as the initial stages of growth. In technical applications. the ability to produce films having structure similar to that of the solid state would usually be an advantage. 44 references. M . D . A.
K. M. Greenland, J. Sci. Instrum., 38 (I), Jan. 1961, 1-11. 30 : 45 80. Welding of conducting electrodes to thin metallic films. S. Dembicka-Jellonkowa, J. ScL lnstrum., 38 (2), Feb. 1961, 62.
30 : 49 81. A simple method of monitoring the rate of deposition of a conducting film in a vacuum chamber. K. Feldmesser, J. Sci. Instrun,., 38 ~3), March 1961, 104. 30:19
Fiber optics.
IX. Waveguide effects.
See Abstr. No. 40.
30:19 Transmission properties of optical fibers. See Abstr. No. 41.
Multiple-~avelength multiple-beam interferometric on fiat surfaces. See Abstr. No. 42.
30:19 observation
30:19 Infrared transmittance of crystalline yttrium oxide and related compounds. See Abstr. No. 43. 30:19 Infrared transmittance of strontium titanate from room temperature to --180:C. See Abstr. No. 44.
31.
E v a c u a t i o n and S e a l i n g
31:44 82. Simple method of mounting and stretching thin gauze, sheet or foil f o r use in an electron tube_-. P. A. Einstein, J. Sci. Instrum., 37 (2), Feb. 1960, 67.
32.
Nucleonics
32 83. Isotopic analysis of boron in boron trifluoride by mass spectrometry, and measurement of natural boron 10 concentration. Great Britain. A conventional mass spectrometer is used for precise measurements of the isotope ratios of boron in boron trifluoride samples ~ith widely differing concentrations of boron 10. " Memory " effects caused by the adsorption of boron trifluoride on to the surfaces of the inlet system have been investigated, and it is found that these can be reduced to a workable level by careful design of the inlet system ; the construction of a glass leak for the inlet system is described. The preparation of standard samples is discussed. (Author, modified) P. G. Bentley, J. Sci. Instrum., 37 (9), Sept. 1960, 323-328.
84. Ratiometer for low-current mass spectrometry. Great Britain. This paper describes a technique for measuring isotopic abundance ratios with only a single ion beam and detector. The magnetic field of the conventional spectrometer is adjusted to bring the desired part of the spectrum on to the exit slit of the instrument, while the exact mass of ion passing through the slit is selected by a transverse electric field between two plates reminiscent of the deflexion plates of a cathode-ray tube. To compare the abundance of t ~ o isotopes, the transverse field is switched between two adjustable values so that ions of the required two mass numbers pass alternately through the slit to the detector. The output from each detector is fed to a separate scalar. After a convenient number of complete switching cycles, the indications of the two scalars are proportional to the relative abundances of the two isotopes. A novel form of detector, first introduced by Schutze and Berhardt, is used.