Atomic structure of fivefold twin center in diamond film

Atomic resolution high voltage transmission electron microscopy (ARHVTEM) was applied to a fivefold twin center in diamond film. The atomic structure of the fivefold twin center was the same as that suggested by Matsumoto and Matsui. The structure had no dangling bond. The fivefold-membered ring was observed to be at the center. The location of the fivefold twin center, observed in this study, indicated that it was produced by the meeting of two {111} Σ3 grain boundaries.