Kazumi Ogino

Wettability of MgO single crystal by liquid pure Pb, Sn and Bi

Abstract The wettability of MgO single crystals by liquid metals such as Sn, Pb and Bi was studied at 873 K in a hydrogen atmosphere. It became apparent that wettability was dependent on a crystallographic orientation and a heat treatment of the MgO substrate. The MgO surfaces were observed using an atomic force microscope (AFM) to clarify the effect of the surface arrangement of the substrate on wettability. The results suggest that the surface arrangement of the substrate does indeed affect wettability.

Surface structure of fluorine-graphite intercalation compounds observed by atomic force microscopy

Abstract Atomic force microscopy (AFM) has been used to image fluorine-graphite intercalation compounds (C 3.5 F; stage 1 + 2, C 3.9 F; stage 2, (CF) n ; stage 1). For all samples the atomic resolution is achieved. The AFM image of the C 3.5 F compound exhibits a new orthorhombic superlattice structure ( a = 0.49 nm, b = 0.42 n, ∠ a − b = 90°). In the AFM images of C 3.5 F and (CF) n the protrusions are attributed to fluorine atoms. The AFM image of C 3.9 F exhibits a centered hexagonal structure similar to highly oriented pyrolytic graphite (HOPG).

WETTABILITY OF SILICON CARBIDES BY LIQUID METALS

ABSTRACT The wettability of silicon carbides (a hot-pressed SiC, a reaction-bonded SiC and a single crystal of α-SiC) by liquid metals was investigated using the sessile drop method. Measurements were carried out in Ar atmosphere and in vacuo. Generally, non-wetting contact angles were observed for Pb, Sn, Ag, Ge, and Cu, whereas Si, Fe, Ni, and Co were found to wet. Wetting behaviours of Cu and Ge depended on the surface properties of SiC. In particular, the liquid Cu showed the hexagonal spreading, which was regulated by the surface property of α-SiC, on the single crystal of α-SiC.