Interpretation of electron diffraction patterns from amorphous and fullerene-like carbon allotropes

The short range order in amorphous and fullerene-like carbon compounds has been characterized by selected area electron diffraction (SAED) patterns and compared with simulations of model nanoclusters. Broad rings in SAED pattern from fullerene-like CNx at ∼1.2, ∼2, and ∼3.5 Å indicate short-range order similar to that in graphite, but peak shifts indicate sheet curvature in agreement with high-resolution transmission electron microscopy images. Fullerene-like CPx exhibits rings at ∼1.6 and 2.6 Å, which can be explained if it consists of fragments with short-range order and high curvature similar to that of C20.