STRUCTURE OF NEWLY SYNTHESIZED BC3 FILMS

We have measured the electron energy-loss spectrum (EELS) of BC3 at sub-eV resolution. Important differences between the total density of states of BC3 at the threshold of the K edge, predicted by earlier ab initio calculations, have been observed. We conclude from our measurements that the atomic arrangement in these materials can be described as graphite sheets with B replacing every third C atom. We suggest that further understanding of the electronic structure of BC3 can be derived by comparing such EELS data with calculations of the local density of states of bulk BC3 and including interlayer interaction.