An anomalously large periodicity has been observed in scanning tunneling microscope images of a (00.1) graphite sample. The unusual contrast has hexagonal symmetry, a periodicity of 7.7±0.2 nm and is superimposed on the usual a=0.246 nm atomic spacing of graphite. Current-voltage curves recorded in the scanning tunneling spectroscopy mode from the region showing the superperiodicity exhibit slightly more metallic behavior than those from neighboring normal regions. One possible explanation for the observed periodicity is that it is a rotational moiré pattern resulting from the overlap between a misoriented layer of graphite and the underlying graphite single crystal.

The growth mechanism for small precipitates of A12O3 formed by internal oxidation in the Nb-Al2O3 interface is studied in detail. The observations show that the Nb (001)/Al2O3 (00.1) interface is almost atomically flat and that there are no interface compounds. We suggest that the final layer on the A12O3 side of this interface consists of oxygen atoms. The effects of image forces on misfit dislocations are found to result in a standoff distance between dislocation cores and the interface, in good agreement with the recent theory. The implications of this for the strength of metal-ceramic bonding are discussed.

In order to determine the intrinsic value of magnetic moment, σs, of α″-Fe16N2 compound, the magnetic moment of (α″+α′)-Fe16N2 films is discussed in connection with the degree of N site ordering in nitrogen–martensite. To establish the more general relation between Fe–N martensite structure and σs, the Fe–N system is expanded to Fe–Co–N and Fe–H–N systems. As a result, it is found that (1) The existence of completely the same structure as bulk α″ phase was reconfirmed even in the film form by the precise structural analysis using x-ray diffraction, transmission electron microscopy and Mössbauer analysis, (2) Fe–H martensite was synthesized by using sputtering under Ar+H2 atmosphere, (3) Stable formation of α″-(Fe100−XCoX)16N2 (X=10–30) phase through N site ordering by postannealing is proposed to be fairly difficult due to the sudden decrement of the phase decomposition temperature, Tp.d., of α′-(Fe100−XCoX)–N (X=0–30). Tp.d. of α′-(Fe100−XCoX)–N (X=0–30) phase decreases from 200 °C to RT with increasing Co and N contents, and (4) The intrinsic value of saturation magnetization of the α″-Fe16N2 phase is convinced to be no more than 240 emu/g (≊2.4 μB per Fe atom on average) at 300 K.

The superstructure caused by the charge density wave (CDW) of the nearly commensurate (N. C.) phase in 1TTaS2 is studied in atomic scale by a high resolution electron microscope with image processing system and a selected area electron diffraction method. It is found that the super‐structure of the N. C. phase, which was first observed in the electron diffraction pattern and analyzed theoretically as the discommensurate structure, has an incommensurate structure in a wide area. It is observed that the components of triple CDW are not always in the same mode in three directions and have some anomaly and defects in their components. It is also observed that the fringes due to the superstructure change their direction near the dislocation in the crystal.

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