Fine particles of various metals (Mg, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Cd, Sn, Au, Pb and Bi) were prepared by evaporation in argon gas at low pressure. The evaporation was carried out in an ordinary vacuum evaporation unit using a tungsten wire basket heater, after introducing the gas into the vacuum chamber. The average particle size was controlled by changing the pressure of the argon. Particle diameter varied from about one hundred Angstoms at 1 mm Hg to a few tenths of a micron at 30 mm Hg. It was proved by electron diffraction that the particles of all the metals (except Pb) were not seriously oxidized in the air. Electron micrographs showed well defined crystal habits for some metals, e.g. hexagonal plates for magnesium and cubes for chromium. Remarkable “necklace-like arrangements” were observed for particles of the ferromagnetic metals. Many electron micrographs and diffraction patterns are reproduced to show the size, shape, arrangement and state of oxidation of the particles.

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This paper forms a continuation of the previous paper of almost the same title (Kimoto et al., Japan. J. appl. Phys. 2 (1963) 702). The materials examined include all the metals studied in the previous paper, Mg, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Cd, Sn, Au, Pb and Bi plus the five elements, Be, Ga, Se, In and Te which have been newly added. One of the advances in the present study is the improved purity of the argon used. Thus, beautiful crystal habits have been observed for many of the elements. A small amount of oxygen, for example 0.03 mm Hg of oxygen in 6 mm Hg of argon, caused remarkable deterioration in the crystal habit of the particles. New modifications of crystal structure were found among the particles of chromium aud manganese. A few of the previous results are corrected because they were found to be due to impurities in the argon.

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