Ion-beam-induced amorphous structures in silicon carbide

Atomistic structure of ion-beam-induced amorphous silicon carbide (a-SiC) has been investigated by cross-sectional transmission electron microscopy. The electron intensities of halo patterns recorded on imaging plates were digitized quantitatively to extract reduced interference functions. We demonstrated the relationship between maximum scattering vector (Q_max) measured in scattering experiments and the resolution of the corresponding pair-distribution function by changing Q_max values from 160 to 230 nm^-1. The results revealed that the C-C peak becomes broadened and eventually a shoulder as the Q_max value becomes shorter, indicating that Q_max values of <160 nm^-1 measured in previous studies are not enough to detect C-C homonuclear bonds in a-SiC. We are the first to reveal the existence of C-C and Si-Si homonuclear bonds in a-SiC using a diffraction technique.