A Geometric Constant Defining Shape Transitions of Carbon Nanotubes under Pressure
Abstract
Using constantpressure molecular dynamics simulations, we demonstrate that when a single walled carbon nanotube (SWNT) is under pressure, it undergoes a series of shape transitions, first transforming from a circle to an oval and then from an oval to a peanut. Most remarkable, the ratio of area of tube crosssections at the second transition over that at the first transition appears as a universal constant, independent of either type of tubes (armchair or zigzag) or tube radius. Its accurate value is computed to be g = 0.819469, by formulating a variational geometry problem to represent SWNTs with a family of closed plane curves of fixed length and minimum bending energy. This work is supported by NSF and DOE.
 Publication:

APS March Meeting Abstracts
 Pub Date:
 March 2004
 Bibcode:
 2004APS..MARD17009Z