Hyomen Kagaku
Online ISSN : 1881-4743
Print ISSN : 0388-5321
ISSN-L : 0388-5321
Volume 10, Issue 3
Displaying 1-10 of 10 articles from this issue
  • Shigeyuki HOSOKI, Sumio HOSAKA, Keiji TAKATA, Tsuyoshi HASEGAWA, Setsu ...
    1989Volume 10Issue 3 Pages 156-161
    Published: April 20, 1989
    Released on J-STAGE: November 11, 2009
    JOURNAL FREE ACCESS
    The origin and principle of scanning tunneling microscopy in reviewed. A prototype STM with a three dimensional stage which is able to select sample area and to approach the sample automatically is described, and typical images obtained by the STM are shown. Surface topograph of cleaved MoS2 (0001) shows neat arrangement of sulfur atoms with 0.316 nm lattice constant. Some defects due to vacancies and a dislocation are also distinguished. It is considered that the imaging principle of STM depends on the probe tip and the atomic arrangement of samples. Also 7 × 7 reconstructed structure of Si (111) is shown.
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  • Nobukatsu FUJINO, Shigeo SUMITA
    1989Volume 10Issue 3 Pages 162-170
    Published: April 20, 1989
    Released on J-STAGE: November 11, 2009
    JOURNAL FREE ACCESS
    Recently the integration grade of LSI becomes higher and higher and much higher cleanliness of the surface of silicon wafer is demanded. The contamination on the silicon wafer surface is classified into two kinds, that is, impurity elements like heavy metals or alkaline metals and small particles.
    For the analysis of metallic impurity on the surface, vapor phase decomposition-atomic absorption spectroscopy (VPD-AAS) is effective, and the use of native oxide for the VPD is explained. The lower limits of detecion for total reflection X-ray fluoresscent (TRXF) and secondary ion mass spectrometry (SIMS) were determined with intentionally contaminated wafers.
    Observation of small particles on the surface of silicon wafer by using scanning electron microscope (SEM) is difficult because the particles are so small in size and number. A combined method of surface particle counter (SPC) and SEM is described. SPC is used to locate particle positions. The coordinates of each particle are then converted to SEM coordinates, and thus each particle is observed and analysed. Using this method, the time spent for the particle analysis on wafers is greatly reduced.
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  • Yoshinori KANNO
    1989Volume 10Issue 3 Pages 171-174
    Published: April 20, 1989
    Released on J-STAGE: November 11, 2009
    JOURNAL FREE ACCESS
    Room temperature stability of metastable tetragonal-zirconia microcrystals in their composite ceramics has been argued from the standpoint of the constraint force (σ) of matrix, which was calculated by Eshelby's equation. The equation is based on the assumption that the dispersed particles and matrix are independent each other and then the effect of the interface can be ignored. However it was found that there was no significant relations between the critical size (dc) (an index of stability) of the microcrystals and the constraint force. This means that the interaction (the effect of the interface) between the dispersed particles and the matrix cannot be ignored in these materials. The t→m phase transformation of ZrO2 was influenced by not only “matrix effect” and “surface energy one” but also “interface one”. It was insisted that a kinetical discussion was also important in analysing the transformation mechanism. It seems to be probable that the field strength (Z/a2) of the metal ions existing in the interfacial layer effects on the dc value.
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  • Noritaka MIZUNO, Kei INUMARU, Makoto MISONO
    1989Volume 10Issue 3 Pages 175-180
    Published: April 20, 1989
    Released on J-STAGE: November 11, 2009
    JOURNAL FREE ACCESS
    Characteristics of H3PMo12O40 and its salts used as humidity sensor has been studied at 20°C. Comparatively rapid response was obtained for thin-films of Cs3PMo12O40 and {(CH3) 2NH0} 3PMo12O40. As the relative humidity changed from 0 to 90%, the impedance decreased by a factor of 103. The resistance-humidity correlation is greatly changed by cation-substitution. Based on the comparison of these resistance-humidity correlations and adsorption (absorption) properties, it was revealed that the resistance depends on the amount of the adsorbed (absorbed) water and that there are three different mechanisms of water adsorption (absorption) : (1) Capillary condensation in micro and mesopores (e. g., Cs3PMo12O40 and {(CH3) 2NH2} 3PMo12O40). (In this case the logarithm of impedance changed almost linearly with the relative humidity). (2) Adsorption without capillary condensation on hydrophilic surface (e.g., (NH4) 3PMo12O40). (3) Absorption into the bulk (e. g., H3PMo12O40 and Na3PMo12O40).
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  • Tsutomu KAJITA
    1989Volume 10Issue 3 Pages 181-186
    Published: April 20, 1989
    Released on J-STAGE: November 11, 2009
    JOURNAL FREE ACCESS
    Calcium oxalate tri-hydrate films have been formed on stainless steel electrodes by polarizing them slightly cathodically in a dilute aqueous solution containing Ca2+ ions and dimethyl oxalate. The solutions were supersaturated with CaC2O4, which was produced as a result of the hydrolysis of dimethyl oxalate and was sparingly soluble. Supersaturation was kept during the film formation. It was found that the electrodeposition rates of CaC2O43H2O were determined by the degree of supersaturation and current density. The degree of the supersaturation which depends on the concentration of reagents and the temperature, influenced on the electrodeposition rate to a greater extent than the current density. The films thus can be formed from the dilute aqueous solutions and at the very low current density.
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  • Yoshizo INOMATA
    1989Volume 10Issue 3 Pages 187-194
    Published: April 20, 1989
    Released on J-STAGE: November 11, 2009
    JOURNAL FREE ACCESS
    An extended formulation of rate equation is proposed so as to treat the rate process in a heterogeneous system, such as crack propagation velocity in brittle fracture. The proposal can be applied for a process in which the excess energy stored in the system is directly relaxed by the reaction. The generalized expression is given as follows,
    υ=ƒ·exp (-ΔGa/RT) ·ψ· {1-exp (-ΔG0/RT)}
    where, ν; velocity of the reaction, ƒ; frequency factor, ΔGa; activation energy, ψ; measure unit of the reaction rate remarked (i. e. lattice parameter, in case of crack propagation), ΔG0; excess energy stored in the system which is finally relaxed through the reaction.
    The term expressed in the parenthesis, corresponds to an effective probability of transformation and it becomes zero under equilibrium state. By the expression, the equilibrium and the rate process can be treated continuously.
    Assuming linear elasticity and Griffith type crack in SiC single crystal, the relationships between stress-crack length-rate of crack propagation and stress-crack length-time to failure are numerically calculated, and the results are discussed. An example of actual application of the present proposal is shown.
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  • Kazutoshi NAGAI
    1989Volume 10Issue 3 Pages 195-201
    Published: April 20, 1989
    Released on J-STAGE: November 11, 2009
    JOURNAL FREE ACCESS
    PMMA, polybutadiene and epoxy resin have been analyzed by using a FAB-SIMS. This technique enables the mass analysis of these thermolabile plastics without any trouble caused by electric charging on the sample surface. It is shown through the in-situ measurement of mass spectra of the residual gas, that neither thermal decomposition nor thermal degeneration of the samples occur through the bombardment with the fast atom primary beam.
    A simulation for the electric charging on insulator surfaces has been tried with an electrically equivalent circuit for the insulators bombarded by ions and by fast atoms. The results are compared with the experimental data obtained by the deflection of a focused electron beam which passed near the charged sample surface.
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  • Shinji SAKUMA, Hiroyuki OHSHIMA, Tamotsu KONDO
    1989Volume 10Issue 3 Pages 202-205
    Published: April 20, 1989
    Released on J-STAGE: November 11, 2009
    JOURNAL FREE ACCESS
    The fixed-charge distribution within the membrane of poly (N, N-L-lysinediylterephthaloyl) microcapsules was examined through zeta potential measurements on the microcapsules at varying pH and ionic strengths of the medium. The zeta potential data obtained were analyzed using a membrane model which assumes that the membrane fixed-charges are distributed to a certain depth and the electrolyte ions can penetrate into the charged layer. As a result, it was revealed that the positive fixed-charges arising from the amino groups of the constituent polymers of the microcapsules are distributed uniformly, and that the negative fixed-charges arising from the carboxylic acid groups of the constituent polymers are concentrated on the surface of the membrane.
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  • Shin-ichi ISHI, Yukio OKWAMOTO
    1989Volume 10Issue 3 Pages 206-208
    Published: April 20, 1989
    Released on J-STAGE: November 11, 2009
    JOURNAL FREE ACCESS
    It is shown that the layer-dependent shifts of xenon's 5 p binding energy observed with photoelectron spectroscopy are due to the “final-state” effect from a veiw of “initial-state-final-state” approach. We have compared and discussed the present treatment with that recently published by Jacobi.
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  • Akira KITANI, Kazuo SASAKI
    1989Volume 10Issue 3 Pages 209-211
    Published: April 20, 1989
    Released on J-STAGE: November 11, 2009
    JOURNAL FREE ACCESS
    The basic concept of organic batteries utilizing conducting polymers was briefly explained.
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