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Electron beam evaporation of a permalloy
Classified abstracts 792-803 means of an ionization chamber. The active gases pass through filters on their way to the ionization chamber, and the radioactivity in these may also be checked. Checking a single fuel-element assembly takes I h. I F Barehuck and D T Plllpets, Atomn Energiya, No 12, 1966, 514 (in
Russian). 27 792. Testing the vacuum-tightness of welds and parent metal in various structures by means of halide leak detectors (GTI-3 and VAGTI-4 types). (USSR) Method of testing welded metal components for vacuum-tightness by means of portable halide leak detectors are described. The basic principle of these detectors is that the flow of positive ions emitted by platinum electrodes at 800-900°C is greatly intensified when halidecontaining gases are present in the surrounding atmosphere. The sensitive element of the leak detectors is accordingly a diode with platinum electrodes. Soviet-manufactured leak detectors of the GTI-3 and VAGTI-4 types compare favourably with analogous devices originating in other countries, not only in their ultimate sensitivity hut also in the rate at which metal components such as welded tubes and pipes may be tested. V ! Zaitsev et al, Defektoskopiya, No 6, 1966, 50 (in Russian). 27 : 34 793. Uslngradlokrypton fordelectionofleaksinspaeevehicles. (USA) The document is a guide for acquiring and using radiokrypton as a leak detection medium for testing space vehicles system and related components. Included are a procedure for the dilution of radiokrypton to a usable concentration, charts and graphs indicating leak rate measurements which were made with the various types of commercial equipment available and a sample test procedure using radioactive test ~as. Anon. Michigan Univ, Rep NASA-CR-77304; IN-R-QUAL-66-6; June 1966. 27 794. A method for discriminating between air and vapour leaks in a vacuum system. (Great Britain) The fact that the pumping speed of a rotary pump is very much greater for a I~erfect gas than it is for a vapour is the basis of a simple rapid method for discriminating between air and vapour leaks in a vacuum system. A H Mellraith and A D C Scott, J Sci lnstrum, 43, 1966, 961.
28. HEATING E Q U I P M E N T AND THERMOMETERS 28 • 20 Laboratory electron furnace. See abstract number 731. 28 : 30 795. Electron beam evaporation of a permalloy. (USSR) Thin permalloy films were nrepared by means of bombarding permalloy rods (diameter 20 x 100 ram) by an electron beam with power up to 3 kW, focused on an area of dimensions of 7 × .7 ram. Rate of evaporation was 1 g/rain and the coating was deposited at 10-5 torr. The composition of the thin films was determined and variations were within the experimental error of +0.2 per cent. M I Vino~radov and V F Ul'yanov, Pribory Tekh Eksper, 11 (6), NovDec 1966, 210-211 (in Russian). 28 796. Device for high temperature metullography in gas or vacuum. (USSR) A small laboratory device that can be filled by an inert gas or pumped down to 5 × I0 -6 tort is briefly described. A sample of dimensions 5 × I0 × 15 mm can be heated up to 1,100°C with accuracy of 4-I°C. (USSR). Yu D Chistyakov and V V Pankratov, Zavodsk Lab, 32 (12), Dec 1966, 1539-1540 (in Russian). 28 797. A cryofurnace for Mossbauer spectroscopy. (Israel) A vacuum cryofurnace for Mossbauer effect studies permitting temperature control from 85°K to 870~K is described. Any temperature in this range can be maintained for long periods, utilizingan appropriate electronic temperature stabilizer. Temperature inhomogeneity over the sample is estimated to be less than I°K. This cryostat can transmit radiation with a conical angle of 12°. The operation of the cryofurnace permits quick interchan~in~ of samnles. B Sharon and D Treves, Rep TN-17- AD632751, Au,e 1965 (Weizmann
Inst of Science, Rehovoth, Israel,Dept of Electronics).
28 798. Low temperature measurements using semiconductors. (Hungary) Semiconductor, cryogenic, resistance thermometers are made from single crystal p-type, germanium doped with 3.8 × 10~e/cms gallium and 3 x 10t~/cmS antimony. The material has a dislocation density of 3000/cm 2. Construction and operational details are described. P Szebeni, Hiradastech Ipari Kutao lnt Kozlemeny, 6, 1966, 59-68 (in
Hungarian). 28 799. Oxidized nickel as a heating element in a vacuum. (Great Britain) An investigation has been made in vacuum of the thermal radiating capacity of nickel with different degrees of oxidation, the nickel being heated from 700 ° to the burn-out temperature. Evaporation and evolution of gases at elevated temperatures, which are considered to restrict the functioning of oxidized nickel as a good heating element, are discussed. H Y Wong, BritJApplPhys, 17, 1966, 1329-1337.
III. Vacuum applications 30. EVAPORATION AND SPUTTERING 30:20 Diffractometer URS-50-1M vacuum accessory for thin film Investigations during sputtering. See abstract number 730. 30 : 28 Electron beam evaporation of a permalloy. See abstract number 795. 30 800. Structure of verv thin tantalum and molybdenum films. (USA) Observation of thin film ~rowlh in a continuously recording electron diffraction instrument shows fee nhases in very thin films of Ta and Mo. The bcc plane is first detected in films 40 and 80 ,~ thick for Mo and Ta respectively: no fcc Ta has been detected in films thicker than 250 •. Fee Ta films have been prenared in another high vacuum station on different substrates at various temperatures. Epitaxial fcc Ta has been grown on M~O. P N Denblgh and R B Marcus, J dppl Phys, 37, 1966, 4325-4330. 3O 801. Role of condensation phenomenon in the measurement of film thickness by the oscillating quartz crystal method. (USA) The deposition of thin layers of ZnS and MgF~ on each other and on a glass surface was studied. The rate of evaporation, the film thickne~, and the reflection of the layers were measured simultaneously. Condensation effects were found to influence the formation of layers on different substrates, a fact which has to be taken into account in measurements using an oscillatin~ auartz crystal technique. J Bakos et al, J Appl Phys, 37, 1966, 4433-4436. 3O 802. Vacuum deposited magnetic thin films of FesO4-BzO~ mixtures. (USA) Films of Fe.~O,-B~O3 varying in starting composition of 100 per cent to 90 per cent Fe,O, mixed with 0 per cent to 10 per cent B,O.~ proportionally by weight were deposited from W boats at a pressure of 2× l0 -s tort. It was found that the minimum B=Os content was 5 per cent for which films deposited from the mixture exhibited pronerties identifiable as those of ma~,netite. X-ray and electron beam diffraction studies showed that films deposited from the 9515 mixture and annealed in vacuum to teml~eratures up to 520°C were amorphous, but magnetite structure of increasin~ cr~stallinity was observed at hi,,her annealing temr)eratures ut~ to 750°C. M Hacskaylo, J ,4ppl Phys, 37, 1966, 4536-4542. 3O 803. Evaporation and del~ition rates, stiekin~ probabilities and back~ound pressure during the production of thin films in vacuum. (USA) The evalaoration ratemeter described is used in a special circuit so that the background pressure and the rate of evanoration can be monitored simultaneously and continuously with the same specially desi~med ionization gauge. Both can be displayed on the ~reen of an oscilloscope or recorder; the rate appears as an arc ripple superimposed on the dc signal which is a measure of the background pressure at the substrate. A quartz oscillator ratemeter is used to measure the deposition rate. From the readings of two ratemeters the sticking probability has been determined. H Sehwur-z, J .4ppl Phys, 37, 1966, 4341-4346.
251
Russian). 27 792. Testing the vacuum-tightness of welds and parent metal in various structures by means of halide leak detectors (GTI-3 and VAGTI-4 types). (USSR) Method of testing welded metal components for vacuum-tightness by means of portable halide leak detectors are described. The basic principle of these detectors is that the flow of positive ions emitted by platinum electrodes at 800-900°C is greatly intensified when halidecontaining gases are present in the surrounding atmosphere. The sensitive element of the leak detectors is accordingly a diode with platinum electrodes. Soviet-manufactured leak detectors of the GTI-3 and VAGTI-4 types compare favourably with analogous devices originating in other countries, not only in their ultimate sensitivity hut also in the rate at which metal components such as welded tubes and pipes may be tested. V ! Zaitsev et al, Defektoskopiya, No 6, 1966, 50 (in Russian). 27 : 34 793. Uslngradlokrypton fordelectionofleaksinspaeevehicles. (USA) The document is a guide for acquiring and using radiokrypton as a leak detection medium for testing space vehicles system and related components. Included are a procedure for the dilution of radiokrypton to a usable concentration, charts and graphs indicating leak rate measurements which were made with the various types of commercial equipment available and a sample test procedure using radioactive test ~as. Anon. Michigan Univ, Rep NASA-CR-77304; IN-R-QUAL-66-6; June 1966. 27 794. A method for discriminating between air and vapour leaks in a vacuum system. (Great Britain) The fact that the pumping speed of a rotary pump is very much greater for a I~erfect gas than it is for a vapour is the basis of a simple rapid method for discriminating between air and vapour leaks in a vacuum system. A H Mellraith and A D C Scott, J Sci lnstrum, 43, 1966, 961.
28. HEATING E Q U I P M E N T AND THERMOMETERS 28 • 20 Laboratory electron furnace. See abstract number 731. 28 : 30 795. Electron beam evaporation of a permalloy. (USSR) Thin permalloy films were nrepared by means of bombarding permalloy rods (diameter 20 x 100 ram) by an electron beam with power up to 3 kW, focused on an area of dimensions of 7 × .7 ram. Rate of evaporation was 1 g/rain and the coating was deposited at 10-5 torr. The composition of the thin films was determined and variations were within the experimental error of +0.2 per cent. M I Vino~radov and V F Ul'yanov, Pribory Tekh Eksper, 11 (6), NovDec 1966, 210-211 (in Russian). 28 796. Device for high temperature metullography in gas or vacuum. (USSR) A small laboratory device that can be filled by an inert gas or pumped down to 5 × I0 -6 tort is briefly described. A sample of dimensions 5 × I0 × 15 mm can be heated up to 1,100°C with accuracy of 4-I°C. (USSR). Yu D Chistyakov and V V Pankratov, Zavodsk Lab, 32 (12), Dec 1966, 1539-1540 (in Russian). 28 797. A cryofurnace for Mossbauer spectroscopy. (Israel) A vacuum cryofurnace for Mossbauer effect studies permitting temperature control from 85°K to 870~K is described. Any temperature in this range can be maintained for long periods, utilizingan appropriate electronic temperature stabilizer. Temperature inhomogeneity over the sample is estimated to be less than I°K. This cryostat can transmit radiation with a conical angle of 12°. The operation of the cryofurnace permits quick interchan~in~ of samnles. B Sharon and D Treves, Rep TN-17- AD632751, Au,e 1965 (Weizmann
Inst of Science, Rehovoth, Israel,Dept of Electronics).
28 798. Low temperature measurements using semiconductors. (Hungary) Semiconductor, cryogenic, resistance thermometers are made from single crystal p-type, germanium doped with 3.8 × 10~e/cms gallium and 3 x 10t~/cmS antimony. The material has a dislocation density of 3000/cm 2. Construction and operational details are described. P Szebeni, Hiradastech Ipari Kutao lnt Kozlemeny, 6, 1966, 59-68 (in
Hungarian). 28 799. Oxidized nickel as a heating element in a vacuum. (Great Britain) An investigation has been made in vacuum of the thermal radiating capacity of nickel with different degrees of oxidation, the nickel being heated from 700 ° to the burn-out temperature. Evaporation and evolution of gases at elevated temperatures, which are considered to restrict the functioning of oxidized nickel as a good heating element, are discussed. H Y Wong, BritJApplPhys, 17, 1966, 1329-1337.
III. Vacuum applications 30. EVAPORATION AND SPUTTERING 30:20 Diffractometer URS-50-1M vacuum accessory for thin film Investigations during sputtering. See abstract number 730. 30 : 28 Electron beam evaporation of a permalloy. See abstract number 795. 30 800. Structure of verv thin tantalum and molybdenum films. (USA) Observation of thin film ~rowlh in a continuously recording electron diffraction instrument shows fee nhases in very thin films of Ta and Mo. The bcc plane is first detected in films 40 and 80 ,~ thick for Mo and Ta respectively: no fcc Ta has been detected in films thicker than 250 •. Fee Ta films have been prenared in another high vacuum station on different substrates at various temperatures. Epitaxial fcc Ta has been grown on M~O. P N Denblgh and R B Marcus, J dppl Phys, 37, 1966, 4325-4330. 3O 801. Role of condensation phenomenon in the measurement of film thickness by the oscillating quartz crystal method. (USA) The deposition of thin layers of ZnS and MgF~ on each other and on a glass surface was studied. The rate of evaporation, the film thickne~, and the reflection of the layers were measured simultaneously. Condensation effects were found to influence the formation of layers on different substrates, a fact which has to be taken into account in measurements using an oscillatin~ auartz crystal technique. J Bakos et al, J Appl Phys, 37, 1966, 4433-4436. 3O 802. Vacuum deposited magnetic thin films of FesO4-BzO~ mixtures. (USA) Films of Fe.~O,-B~O3 varying in starting composition of 100 per cent to 90 per cent Fe,O, mixed with 0 per cent to 10 per cent B,O.~ proportionally by weight were deposited from W boats at a pressure of 2× l0 -s tort. It was found that the minimum B=Os content was 5 per cent for which films deposited from the mixture exhibited pronerties identifiable as those of ma~,netite. X-ray and electron beam diffraction studies showed that films deposited from the 9515 mixture and annealed in vacuum to teml~eratures up to 520°C were amorphous, but magnetite structure of increasin~ cr~stallinity was observed at hi,,her annealing temr)eratures ut~ to 750°C. M Hacskaylo, J ,4ppl Phys, 37, 1966, 4536-4542. 3O 803. Evaporation and del~ition rates, stiekin~ probabilities and back~ound pressure during the production of thin films in vacuum. (USA) The evalaoration ratemeter described is used in a special circuit so that the background pressure and the rate of evanoration can be monitored simultaneously and continuously with the same specially desi~med ionization gauge. Both can be displayed on the ~reen of an oscilloscope or recorder; the rate appears as an arc ripple superimposed on the dc signal which is a measure of the background pressure at the substrate. A quartz oscillator ratemeter is used to measure the deposition rate. From the readings of two ratemeters the sticking probability has been determined. H Sehwur-z, J .4ppl Phys, 37, 1966, 4341-4346.
251