Electron energy loss near-edge structures of cubic Si3N4

Electron energy loss near-edge structures of the newly discovered cubic-Si3 N4 at the Si L-2,L-3, edge and N K edge have been measured. The same edges were calculated using a first-principles supercell approach, including the core-hole interaction. The experimental spectra at the two edges were satis factorily reproduced by the calculations, confirming that the present calcu lation has sufficient predictive power. The difference in spectral shapes b etween c-Si3N4 and beta -Si3N4 is more clear for the Si L-2,L-3, edge. Howe ver, the difference cannot be simply explained by the difference in coordin ation numbers of Si. (C) 2001 American Institute of Physics.