表面科学
Online ISSN : 1881-4743
Print ISSN : 0388-5321
ISSN-L : 0388-5321
7 巻 , 5 号
選択された号の論文の6件中1~6を表示しています
  • 舘脇 洋
    1986 年 7 巻 5 号 p. 370-382
    発行日: 1986/11/20
    公開日: 2009/11/11
    ジャーナル フリー
    The electronic structure of the transition metal clusters Ni1-Ni6, Cu1-Cu6, and Zn1-Zn6 is studied by ab initio SCF calculations. The configuration interaction calculations are also performed for Zn and Ni clusters. In this paper, density of the states (DOS) is discussed in detail. Using the Koopmans' theorem, we found that the d-band is completely separated from the s-band for the Cu clusters. Also, DOS given by ΔSCF with the symmetry adopted SCF calculations is parallel to that given by the Koopmans' theorem. We note that d-electrons are bound near to the nucleus compared with 4s electrons. When a d-electron is ionized, a resulting d-hole might be localized at one of the constituent atoms of the clusters. Such a model probably gives a better description for the d-electron ionization so far as the one electron approximation is employed. The calculated results for the Cu clusters meet our expectations. The resulting d-band is embedded in the 4s-band for the Cu clusters and DOS of the clusters resemble that of metal Cu. Similar results are found for the Ni and Zn clusters. It will be, however, dicussed that the Fermi level of the small clusters is somewhat larger (deeper) than that of the metals.
  • 小倉 〓, 林 精一, 蓬田 和夫
    1986 年 7 巻 5 号 p. 383-389
    発行日: 1986/11/20
    公開日: 2009/11/11
    ジャーナル フリー
    Evaporated Ag thin films are formed on cleaved or deposited NaCl surfaces in Ar gas atmospheres at about 1 Pa. The results of this experiment and some others which have recently been obtained in our laboratory are discussed with relation to stimulated surface migrations of Ag adatoms and clusters on the substrate. Discussions are as follows:
    (1) The temperature of the substrate surface is raised by less than 1K, even though the temperature of Ar gas is raised to 800K.
    (2) Adatoms and clusters migrate to Cl- ion vacancies at step ledges along [010]NaCl direction and on (001)NaCl facets.
    (3) Ag 4 atom clusters at the vacancies grow into embryos of (110) or (001) oriented Ag particles.
    (4) Graphoepitaxial orientation with [001] (110)Ag//[100] (001)NaCl is attributed to step ledges along [010]NaCl direction.
    (5) Pentagonal particles are initiated by multi-twinned particles.
  • 奥村 統, 大久保 利長, 中川 龍一, 鶴田 康生, 西尾 宏
    1986 年 7 巻 5 号 p. 390-396
    発行日: 1986/11/20
    公開日: 2009/11/11
    ジャーナル フリー
    Caking phenomenon of laundry granular detergent after a storage in the cartons under high temperature and high humidity was examined with regard to the change of humidity and temperature in the layers of detergent particles. It was disclosed that the humidity in the cartons varied with the atmospheric temperature and the caking of detergent had developed without moisture adsorption from the atmosphere. With rising temperature in the carton, the specific resistivity of conductance for the packed detergent decreased rapidly. So, it suggests that the number of ions in the water film increased due to the dissolved detergent components in the water film surrounding the surface of granular detergent. Meanwhile, SEM photographs showed the formation of solid bridges among the detergent particles.
    It was concluded that the caking processes comprised the following steps: (1) dehydration of detergent components with temperature rising, (2) dissolution of the surface components of the granular detergent by water, and formation of the liquid bridges among the particles, (3) water uptake by crystalline materials with temperature reduction, and (4) transformation of liquid bridges to solid bridges.
  • 中林 一朗
    1986 年 7 巻 5 号 p. 397-403
    発行日: 1986/11/20
    公開日: 2009/11/11
    ジャーナル フリー
    Acetone hydrogenation was investigated by plate-type Raney nickel and iron catalysts. Various parameters such as crystallite size, surface area and magnetic properties were studied, and their analysis was carried out by EPMA, SEM, X-ray diffractometer and magnetometer. The alloy layers were formed at the boundary when molten aluminum was sprayed over the surface of the nickel and iron plates and then the plates were heated. Raney catalysts were prepared by leaching aluminum from the above alloy with an aqueous alkaline solution. The catalyst prepared by leaching NiAl3 may give the highest activity per unit of surface area.
    Ni-Al alloy is paramagnetic, while Raney nickel which is leached aluminum from Ni-Al alloy has superparamagnetic property, i.e., the saturated magnetization is smaller than that of original nickel. The Raney nickel catalyst has an unchanged Curie point. Measurements of Curie point reveal that Raney iron catalyst (SUS 304) exhibits high hydrogenation activity at Fe-Cr-Ni solid solution state.
  • 左右田 龍太郎
    1986 年 7 巻 5 号 p. 404-411
    発行日: 1986/11/20
    公開日: 2009/11/11
    ジャーナル フリー
    Low-energy rare-gas Ion Scattering Spectroscopy (ISS) has been improved by the use of neutral beams as projectiles, which we call Neutral Beam Incidence Ion Scattering Spectroscopy (NBISS).Experiments on ISS and NBISS are compared on the basis of electron exchange between the projectiles and solid surfaces.
    In ISS, the scattered ions consist of two elements: One is “surviving ions” characterized by the ions which survived neutralization, and the other is “reionized ions” characterized by those which experienced neutralization on the incoming trajectory and subsequent reionization during the violent collision. The shadowing and focusing effects are often weakened in the intensity of surviving ions, whereas these effects appear intensively in the intensity of reionized ions. Since the threshold energy for the reionization is different for the combination of projectiles and targets, these effects are often not observed at all in the ISS spectra. On the other hand, these effects appear explicitly in the NBISS spectra. It is also found that NBISS is valid for analyzing insulator surfaces since charging effects are minimized by the use of neutral beams.
  • 鈴木 喜久, 羽生 孔昭, 恒川 清爾, 前島 浩
    1986 年 7 巻 5 号 p. 412-416
    発行日: 1986/11/20
    公開日: 2009/11/11
    ジャーナル フリー
    In a few cases, we have had troubles with magnetic tape stations, such as unusual tape movement. After research on this problem, we have found a cause for these accidents.
    We found the existence of sticky materials of molecular weight (several ten thousands) in the tape was the potential factor. The factor can be assessed by running the extract of tape by Freon TMC® through a gell permeation chromatograph.
    In practice the trouble occurs combining it with the factors of equipment and environment. Thus, we developed what we call a “Press Binding Test”, employing these constant factors, as a good evaluation method to assess the surface of the magnetic tapes.
    Although only a small fraction of the magnetic tapes passed this test about 10 years ago, almost all of the recent new computer tapes have pass this test.
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