Carbon-atom chain formation in the core of nanotubes

Here we report the observation of a linear carbon-atom chain, synthesized u sing an are discharge from a graphite double anode. We use high-resolution TEM to evidence the formation of a carbon-atom chain along the axis of a ne edlelike structure consisting of concentric cylindrical graphitic shells. T he atomic chain in the core of the innermost cylinder, by calculations on t he basis of van der Waals interactions, demonstrates an extremely high ther mal stability (up to 4200 K) and exhibits high mechanical strains.