Resonant soft-x-ray emission study in relation to the band structure of cBN

Abstract
The resonant soft-x-ray emission (SXE) and its total photon yield (TPY) spectra were measured at the B 1s and N 1s edges of cubic boron nitride (cBN) using undulator radiation. The band-gap energy was found to be about 6.2 eV, which is in good agreement with other experiments. It was found that the emission from the high symmetry point in the SXE spectrum is enhanced when the same high symmetry point in the TPY spectrum is excited. The line shapes in both the SXE and N 1s TPY spectra were consistent with the calculated partial density of states, though the total bandwidth was not well reproduced. On the other hand, the exciton effect was found to be strong in the B 1s TPY spectra.