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Field ion microscope
Classified abstracts 468-481 of the oxide layers formed on the surface of germanium single crystals is investigated with the aid of an electron microscope. J Giber et al, Acta Chim Acad Sci Hung 63 (3), 1970, 279-291. 33 468. X-ray diffraction investigation of diamonds treated by ion bombardment. (USSR) Using X-ray diffraction techniques, the influence of 40 keV lithium ion bombardment (10 TM cm -~ dosage) on the crystal structure of natural diamond is investigated. It is found that ion bombardment gives rise to a thin surface layer with highly disturbed crystal structure. M I Guseva et al, Kristallografiya, 15 (3), 1970, 523-527 (in Russian). 33 469. Experimental investigation of a thin electron beam with high specific power in crossover. (USSR) A thin electron beam with a diameter of 20 to 5 0 / t i n with a high specific power of 106 to l0 s W/cm ~ in crossover is investigated with the aid of a scanning diaphragm. Experiments are carried out on an electron beam equipment for machining of materials. It is found that the electron beam formed by a triode gun has a current density distribution corresponding to Gauss law. N T Ostroverkhov et al, Elektron Tekh Elektran SVCh, 7, 1970, 46-51 (in Russian). 33 470. Analysis of the transitional region of the heating characteristic of a nonuniform cathode. (USSR) An analysis of the transitional region of the heating characteristic of a nonuniform cathode in the region from the temperature limited to the space charge limited regime is performed. S P Klodnevich, Elektron Tekh Elektran SVCh, 7, 1970, 132-139 (in
Russian). 33 471. Measurement of variable micro-fields in an emission microscope. (USSR) For measurement of time varying electrical micro-fields on semiconductors, a method of field determination, utilizing image contrast in an emission electron microscope operated in the stroboscopic regime, is presented. Measurement of fields and potentials on silicon diodes under pulsed operation is demonstrated. N N Sedov et al, Vestnik Mosk Universit, Fiz Astronom, 11 (2), 1970, 230-232 (in Russian). 33 472. Laboratory electron gun. (USSR) Construction of a laboratory electron gun with an electrostatic focusing system is described. The gun can operate both with the space charge limited current and the temperature limited current. The beam current in the space charge limited region is controlled by cathode position and in the temperature limited region by cathode temperature. The beam current can also be modulated with the aid of the focusing electrode. P D Stavrianidi, Trudy Institut Elektron Avtomat Telemekh Akad Nauk Gruz SSR, 8 (2), 1970, 72-78 (in Russian). 33 473. Ion gun for ultrahigh frequency devices. (USSR) An ion gun for ultrahigh frequency devices giving proton currents up to 5 m A is described. V A Tsarev and E V Anisimov, Elektronnaya Promyshlennost, No 1, 1970, 77 (in Russian). 33 474. Vacuum cuvette for investigation of infrared absorption spectra (USSR) A metallic cuvette for investigation of infrared absorption spectra in high vacuum and at different temperatures from --30 to 450°C, is described. A mercury diffusion pump maintains pressure of 1 0 J tort in the cuvette. V A Petrichenko and V I Kiselev, Prib Tekh Eksper, No 3, May/June 1970, 278 (in Russian). 33 475. Improved evaporator for the EG-100M electrongraph. (USSR) An evaporator for the EG-100M electrongraph is described which is intended for investigation of the structure of organic compounds in the gas phase. The evaporator can be used in the temperature range from room temperature to 350°C. A needle valve reduces losses of material during evacuation. N V Fomin et ai, Prib Tekh Eksper, No 3, May/June 1970, 272 (in
Russian).
476. Scanning (USSR)
electron
microscope-microanalyzer,
33 REMMA.
An apparatus, designated "REMMA", is described which represents a combination of manning electron microscope with X-ray spectrum microanalyzer. It enables images of a solid surface in secondary and absorbed electrons, and X-ray characteristic radiation to be obtained by scanning the surface with a thin electron probe, and also qualitative analysis of chemical composition of the sample in the range of elements from Mg to U. Working pressure in the chamber is 2 × 10-5 torr. Threshold resolution of the apparatus is 5000 to 700 A for the electron image and 1 to 2/~m for the X-ray image. V A Zelentsov, Prib Tekh Eksper, No 3, May/June 1970, 273 (in
Russian). 33 477. Field ion microscope. (USSR) Glass and metal ion field microscopes are designed to investigate a single sample in one working cycle. Often, for example in the investigation of a determined kind of defect, for which the probability of occurrence is small, a great number of samples must be investigated involving great expense. The design of an all-metal field ion microscope is described which permits the investigation of six prepared samples in an arbitrary order without heating the system or breaking the vacuum. Also, repeated observation of an arbitrary sample is possible. The field ion microscope is pumped by an oil diffusion pump with a pumping speed of 500 litres/sec. Utilization of a liquid nitrogen trap provides a pressure of 5 × 10-¢ torr in the vacuum chamber. A charcoal sorption pump may also be used to maintain high vacuum. The samples are cooled by liquid nitrogen, hydrogen or helium. The investigated samples are placed in a revolving holder, and can be heated to a temperature of 3000°C in the working position. The high voltage supply can be switched on with reversed polarity for the field emission regime. Images of tungsten samples with good resolution are obtained at liquid nitrogen temperature and helium pressure of 6 to 8 × 10-4 torr. R I Garber and G G Checheinitskiy, Prib Tekh Eksper, No 3, May/ June 1970, 237-239 (in Russian). 33 478. A stroboscopic electron microscope with time resolution of 2 nsec. (USSR) A stroboscopic electron microscope for observation of the dynamics of domain structure in thin magnetic films under pulsed remagnetization, is described. Time resolution of 2 nsec is attained. Ya A Durasova et al, Prib Tekh Eksper, No 3, May/June 1970, 233-235
(in Russian). 33 479. Utilization of a diode current signal in a scanning electron microscope. (USSR) A method of obtaining an image of a p-n junction in a scanning electron microscope, based on the diode current signal, is presented. The diode current signal is produced at a division on the p-n junction of charge carriers generated by the electron probe. E B Korob and S A Ditsman, Prib Tekh Eksper, No 3, May/June 1970, 236-237 (in Russian). 33 480. On image formation in the field ion microscope. (USSR) An analysis of image formation in a field ion microscope is carried out taking account of the curvature of ion trajectories of the imaging gas under the influence of the electrostatic field. The image of a semispherical tip is calculated which is in good agreement with experimental results. V I Kirienko and L P Potapov, Prib Tekh Eksper, No 3, May/June 1970, 239-243 (in Russian). 33 481. Estimation of the reliability and life of self-heating devices. (USSR) It is shown that vacuum tubes with self-heating cathodes possess higher reliability than conventional receiving tubes. Application of a thermal shield in the self-heating vacuum tubes prevents local overheating of the glass envelope. The interface layer resistance does not develop in self-heating tubes. V T Aieksandrov et al, Tr 1-oy Yubileyn Resp Mezhvuz Konfer Probl Povysh Effektivn Elektrovakuurn Prib, 1, Kiev 1970, 26-36 (in Russian).
249
Russian). 33 471. Measurement of variable micro-fields in an emission microscope. (USSR) For measurement of time varying electrical micro-fields on semiconductors, a method of field determination, utilizing image contrast in an emission electron microscope operated in the stroboscopic regime, is presented. Measurement of fields and potentials on silicon diodes under pulsed operation is demonstrated. N N Sedov et al, Vestnik Mosk Universit, Fiz Astronom, 11 (2), 1970, 230-232 (in Russian). 33 472. Laboratory electron gun. (USSR) Construction of a laboratory electron gun with an electrostatic focusing system is described. The gun can operate both with the space charge limited current and the temperature limited current. The beam current in the space charge limited region is controlled by cathode position and in the temperature limited region by cathode temperature. The beam current can also be modulated with the aid of the focusing electrode. P D Stavrianidi, Trudy Institut Elektron Avtomat Telemekh Akad Nauk Gruz SSR, 8 (2), 1970, 72-78 (in Russian). 33 473. Ion gun for ultrahigh frequency devices. (USSR) An ion gun for ultrahigh frequency devices giving proton currents up to 5 m A is described. V A Tsarev and E V Anisimov, Elektronnaya Promyshlennost, No 1, 1970, 77 (in Russian). 33 474. Vacuum cuvette for investigation of infrared absorption spectra (USSR) A metallic cuvette for investigation of infrared absorption spectra in high vacuum and at different temperatures from --30 to 450°C, is described. A mercury diffusion pump maintains pressure of 1 0 J tort in the cuvette. V A Petrichenko and V I Kiselev, Prib Tekh Eksper, No 3, May/June 1970, 278 (in Russian). 33 475. Improved evaporator for the EG-100M electrongraph. (USSR) An evaporator for the EG-100M electrongraph is described which is intended for investigation of the structure of organic compounds in the gas phase. The evaporator can be used in the temperature range from room temperature to 350°C. A needle valve reduces losses of material during evacuation. N V Fomin et ai, Prib Tekh Eksper, No 3, May/June 1970, 272 (in
Russian).
476. Scanning (USSR)
electron
microscope-microanalyzer,
33 REMMA.
An apparatus, designated "REMMA", is described which represents a combination of manning electron microscope with X-ray spectrum microanalyzer. It enables images of a solid surface in secondary and absorbed electrons, and X-ray characteristic radiation to be obtained by scanning the surface with a thin electron probe, and also qualitative analysis of chemical composition of the sample in the range of elements from Mg to U. Working pressure in the chamber is 2 × 10-5 torr. Threshold resolution of the apparatus is 5000 to 700 A for the electron image and 1 to 2/~m for the X-ray image. V A Zelentsov, Prib Tekh Eksper, No 3, May/June 1970, 273 (in
Russian). 33 477. Field ion microscope. (USSR) Glass and metal ion field microscopes are designed to investigate a single sample in one working cycle. Often, for example in the investigation of a determined kind of defect, for which the probability of occurrence is small, a great number of samples must be investigated involving great expense. The design of an all-metal field ion microscope is described which permits the investigation of six prepared samples in an arbitrary order without heating the system or breaking the vacuum. Also, repeated observation of an arbitrary sample is possible. The field ion microscope is pumped by an oil diffusion pump with a pumping speed of 500 litres/sec. Utilization of a liquid nitrogen trap provides a pressure of 5 × 10-¢ torr in the vacuum chamber. A charcoal sorption pump may also be used to maintain high vacuum. The samples are cooled by liquid nitrogen, hydrogen or helium. The investigated samples are placed in a revolving holder, and can be heated to a temperature of 3000°C in the working position. The high voltage supply can be switched on with reversed polarity for the field emission regime. Images of tungsten samples with good resolution are obtained at liquid nitrogen temperature and helium pressure of 6 to 8 × 10-4 torr. R I Garber and G G Checheinitskiy, Prib Tekh Eksper, No 3, May/ June 1970, 237-239 (in Russian). 33 478. A stroboscopic electron microscope with time resolution of 2 nsec. (USSR) A stroboscopic electron microscope for observation of the dynamics of domain structure in thin magnetic films under pulsed remagnetization, is described. Time resolution of 2 nsec is attained. Ya A Durasova et al, Prib Tekh Eksper, No 3, May/June 1970, 233-235
(in Russian). 33 479. Utilization of a diode current signal in a scanning electron microscope. (USSR) A method of obtaining an image of a p-n junction in a scanning electron microscope, based on the diode current signal, is presented. The diode current signal is produced at a division on the p-n junction of charge carriers generated by the electron probe. E B Korob and S A Ditsman, Prib Tekh Eksper, No 3, May/June 1970, 236-237 (in Russian). 33 480. On image formation in the field ion microscope. (USSR) An analysis of image formation in a field ion microscope is carried out taking account of the curvature of ion trajectories of the imaging gas under the influence of the electrostatic field. The image of a semispherical tip is calculated which is in good agreement with experimental results. V I Kirienko and L P Potapov, Prib Tekh Eksper, No 3, May/June 1970, 239-243 (in Russian). 33 481. Estimation of the reliability and life of self-heating devices. (USSR) It is shown that vacuum tubes with self-heating cathodes possess higher reliability than conventional receiving tubes. Application of a thermal shield in the self-heating vacuum tubes prevents local overheating of the glass envelope. The interface layer resistance does not develop in self-heating tubes. V T Aieksandrov et al, Tr 1-oy Yubileyn Resp Mezhvuz Konfer Probl Povysh Effektivn Elektrovakuurn Prib, 1, Kiev 1970, 26-36 (in Russian).
249