Isochromat and SXAPS studies of empty electronic states in chromium, iron and nickel

The density of unoccupied electronic states in Cr, Fe and Ni has been measured employing bremsstrahlung isochromat spectroscopy (BIS) and soft X-ray appearance potential spectroscopy (SXAPS). The LIII core levels were used for the SXAPS measurements. BIS data was taken in the ultraviolet region, the spectrometer energy being 9.7 eV. BIS spectra, after proper correction for electron-hole pair production prior to the radiative process, show encouraging agreement with theoretical calculations and with the density of states derived from the corresponding SXAP spectra by recently developed deconvolution techniques.