Classified abstracts 370--383 of 1 mm reduces the sensitivity by 2-4 × 10-4 g/rad. Details of the vacuum system housing the microbalance are described. The lowest pressure attainable is 10-e torr. The zero point of the balance is affected in an irregular manner by fluctuations in the ambient temperature and by correction current when sample is heated. Buoyancy and desorption effects are difficult to separate and the magnetic field used for damping seems to affect the sensitivity of the balance. It is difficult and yet essential to control all these effects and make full use of the balance. (Japan) (16 references) 14 Ishimura, J Vac Soc Japan, 6 (7), 1963, 268-282, (in Japanese).
30 375. Thin films deposited by bias sputtering. (USA) The application of a negative bias to a film being deposited by dc sputtering produces a film of lower resistivity due to selective removal of adsorbed impurities by positive ion bombardment. Good adhesion of bias sputtered Ta films to glass substitutes is obtained if a smell positive bias is applied initially to the substrate.
( USA ) L I Maissel and P M Schaible, J Appl Phys, 36 (1), 1965, 237-242. 30 : 56 376. Ion migration in glass substrates for electric components.
III. Vacuum applications 30. Evaporation and sputtering 30 Optical properties of thin films of silver between 3.5 and 14 eV. See abstract number 343. 30 Ultrahigh vacuum evaporation using getter ion pumps. See abstract number 352. 30 Thin films. See abstract number 406. 30 370. Ion bombardment coats metals. (Great Britain) Anon, Iron Age, 195 (2), Jan 1965, 66-67. 30 : 41 371. The decay phenomenon of electric resistance of a thin metallic film. (Japan) The films experimented with were of gold, 140 A. thick deposited on a fused quartz substrate 20 x 20 × 3 m m by vacuum evaporation from a tungsten boat. A current stabilizer caused a constant current to flow through the film and changes in resistance are measured automatically by a voltage recorder, the film being at room temperature and in a vacuum of 2-4 × 10-5 torr. The resistance of the film decreases with time, most of the drop being within a minute after deposition. It is suggested that the decay represents reordering of the crystals in the fire and occurs mainly in the grain boundaries of the crystallites. A Kivebara and Y Sawatari, J Vac Soc Japan, 6 (4), 1963, 135-140,
(in Japanese). 30 : 41 372. Epitaxy of cubic metals on alkali halides cleaved in vacuum.
(France) An apparatus is described for cleaving halide crystals in vacuum of 10-6 torr and temperatures up to 900 °. Studies with Au, Ag, A1, Cu, Ni, Fe, Cr and Ge showed that epitaxy could be achieved on the vacuum cleared surfaces at temperatures nearly 200°C lower than those required with air cleavage. Cleavage in vacuum also reduced thermal attack effects. (France) J Jaunet and C Sella, Bull Soc Fran Mineral Cryst, 87 (3), 1964,
393-410. 30 373. Stress in evaporated metallic films. (Japan) The stress measurements were carried out during and after evaporation. In the case of antimony films, a tensile stress is produced in the process of crystallization of amorphous antimony. It is suggested that recrystailization after vacuum deposition plays an important part in producing tensile stresses in metallic films composed of Fe, Ni, Ag, Cu and Au. The origin of the compressive stress, mainly observed in films evaporated on hot substrates is not fully understood. (Japan) (30 references) H Horikoshi and N Tamura, J Vac Soc Japan, 6 (5), 1963, 182-180,
(in Japanese). 3O 374. Determination of stress in films on single crystalline silicon substrates. (USA) Changes in substrate profiles before and after deposition are recorded by means of a light section microscope and from a knowledge of the elastic constants of the substrate, the film stress can be calculated to within A=_10 per cent. (USA) R Glang et al, Rev Sci Instrum, 36 (1), 1965, 7-9.
Experiments with tin oxide resistive films deposited on glass show that the interface electric field promotes ionic movement in the glass. The equilibrium state is sensitive to moisture and temperature and this leads to instability in the ageing characteristic of the resistors. (Great Britain) S M Cox, Phys Chem Glasses, 5 (6), 1964, 161-165. 30:41 377. Magnetic properties of thin permalloy strip films with stripe domain structure. (Japan) The films examined ranged in thickness from 400 to 1200 A. They exhibited regular stripe domains from which the Bloch and N6el wall energy densities could be calculated. For the N6el wall, the density is of the order of 7 erg/cm 2 and for the Bloch wall 1.4 erg/ cm ~. Both figures relate to the 1200 A. film. (Japan) Y Ozaki, J Sci Hiroshima Univ, 28 (1), 1964, 19-34, (in Japanese). 30 : 41 378. Fast flax reversal in laminated nickel-iron thin films. (Great
Britain) Lamination greatly improved the magnetic properties of the films and reduced the reversal times to less than 2tzsec for fields below
( Great Britain)
F B Humphrey and H Clow, Nature, 204, Nov 1964, 769-770. 30 " 41 379. Low temperature antimony evaporator. (USA) A ring source made of molybdenum is recommended for the preparation of large area films. The design ensures a uniform temperature of the source, an important factor to ensure uniformity of deposit. (USA) C A Shifrin and D D Kelly, Rev Sci Instrum, 35 (12), 1964,1712-1713, 30 : 19 : 41 380. Structure and texture of gold films. (USA) The structure and texture of gold films deposited on a neutral substrate by vacuum evaporation were studied with the help of reflection electron diffraction and X-ray diffraction. For deposition temperature between 350 ° and 500 °C, the former method showed extra lines which were not observed by X-ray diffraction. The author suggests that these extra reflections are not due to double diffraction, but are caused by the presence of a hexagonal phase over this temperature range. (USA) J E Davey and R H Deiter, J Appl Phys, 36 (1), 1965, 284-289. 30 : 56 381. Simplified technique for use in multiple thin film deposition systems. (USA) By means of a simple push-pull control through the base plate of the bell jar, the substrates can be rotated to occupy a number of stations corresponding to the number of layers required. (USA) P M Chirlian et al, Rev Sci Instrum, 35 (12), 1964, 1718. 30 : 56 382. Metal generators. (Great Britain) The generators, made available by EMI Electronics, are for depositing small quantities of alkali metal in vacuo. They can be used, for example, for sensitizing photoelectric devices. Each generator consists of a nickel container in a sealed glass ampoule. The container contains a powder which reacts to release alkali metal vapour when the nickel is heated, e.g. by eddy currents. Anon, Electron Equip News, 6, Dec 1964, 43.
31. Evacuation and sealing 31 Alkali triode ion and fast neutral source. Seeabstract number 336. 31 : 51 383. Lasers in interferometry. (USA) This article describes work at the National Bureau of Standards