Direct determination of atomic structure of large-indexed carbon nanotubes by electron diffraction: application to double-walled nanotubes

We report a method for the determination of the chiral indices of large-indexed carbon nanotubes by electron diffraction. By the use of this method, the index assignment errors, originating from the tilt of a nanotube with respect to the incident electron beam, can be directly specified. As an example, the chiral indices of a double-walled nanotubes with index up to 80 and under a high tilt angle of as large as 20° have been accurately identified. Only the data of the maximum peaks of the diffraction layer lines are required in the study, which makes the chiral index determination much easier based on the common diffraction patterns.