Valence Band Emission Spectra of Iron, Cobalt, and Nickel

Abstract

The paper presents results on the shapes of the $M_{2,3}$ emission bands ($\mathrm{valence}\to 3p$) of Fe, Co, and Ni. The relative intensity distributions were arrived at by removing the underlying background contribution in accordance with the predictions made available from recent investigations dealing with the behavior of the soft x-ray bremsstrahlung intensity. In the spectrum of Fe the peak of the composite $M_{2,3}$ band falls at 51.3 ev. The peaks in the Co and Ni spectra are located at 57.8 ev and 64.8 ev, respectively. The high-energy limits are estimated to fall at 56.5 ev, 61.4 ev, and 68.9 ev for Fe, Co, and Ni, respectively. The over-all composite bandwidths in ev in the order of metals just cited are found to be: 14.5, 10.8, and 9.3. These estimates include the low-energy tail belonging to the individual $M_3$ spectral bands. An attempt was made to resolve the Fe $M_{2,3}$ complex band into individual $M_2$ and $M_3$ bands. In this process the inner levels were regarded as sharp, but the influence of Auger reorganization upon the relative band intensities was taken into account. For Fe, this process gives an individual bandwidth of 8.0 ev. The results of the present observations are compared with other determinations of band contours. The various measurements are in agreement as to the location of the peak energy but there are differences in the intensity profiles and bandwidths.