Measurement of radial deformation of single-wall carbon nanotubes induced by intertube van der Waals forces

A cylindrical single-wall carbon nanotube (SWCNT) deforms in a nanotube bundle by van der Waals forces. The deformation is hard to measure, but is required in order to understand the properties of bundles. Here, we show that such deformations can be measured from changes in electron diffraction intensities. We demonstrate this for a bundle of two SWCNTs (d=2.05 and 1.56 nm). Deformation model predicted by atomistic simulations is scaled to fit the experiment. We show that the best fit gives flattening values of 0.7 and 0.35 Å at the middle of the binding surface for the two SWCNTs.