Bending Process and Young's Modulus of Fullerene C60 Nanowhiskers

We performed bending tests on crystalline whiskers composed of fullerene C 60 molecules by in situ transmission electron microscopy with simultaneous measurement of the applied force by an optical deflection method. A C 60 nanowhisker with a diameter of 123 nm was fixed on two fulcra and a concentrated force was applied on the midpoint between the fulcra by the piezomanipulation of a silicon nanotip. The Young's modulus of the nanowhisker was estimated to be 53–69 GPa, 72% smaller than that of C 60 nanotubes. The estimated Young's modulus was plotted against the outer diameter along with the moduli estimated previously by buckling tests on C 60 nanowhiskers. In this relationship, Young's modulus increased as the outer diameter decreased. The result was in agreement with the core–shell model for C 60 nanowhiskers.