Figure 1: a) B
      K-edge x-ray absorption spectra for three BN/Si films. The
      x-ray flux was directed onto the films at normal incidence.
      Notice the 3 small peaks between the pi* peak at
      192.0 eV and the onset of the sigma* band
      at 197 eV.
       b) B K-edge spectra for hBN, cBN, and rBN powders.
    
      
       Figure 2: a) N
      K-edge x-ray absorption spectra for three BN/Si films. All
      data were taken with x-rays at normal incidence.
       b) N K-edge spectra for hBN, cBN, and rBN powders.