High-resolution studies of the K emission spectra of nickel

Abstract

The electron-excited (30 keV) Ni K alpha 1,2, K beta 1,3 and K beta 2,5 spectra have been recorded with a new type of curved crystal spectrometer. High intensity and resolution enabled Lorentzian fits to be introduced, thereby making it possible to estimate the relative contribution of single-vacancy transitions. Difference curves reveal low-energy satellites 2 eV below both alpha 1 and alpha 2, which may be due to unresolved splittings of the L3 and L2 levels, and in part also to the radiative Auger effect K to LV. The low-energy satellite of beta 1,3 may be due to interaction between the final-state hole and the unfilled 3d level, besides the radiative Auger effect K to MV. A high-energy satellite of beta 1,3 is most probably due to a spectator vacancy in the M level or in the valence band V. The K beta 2,5 band has been corrected for background, continuous radiation, self-absorption and overlap with beta 1,3. The intensity maximum of K beta 2,5 is 3.08+or-0.1 eV below the Fermi energy. The observed FWHM value is for alpha 1: 2.22+or-0.05, for alpha 2: 3.14+or-0.05, for beta 1,3: 5.44+or-0.1 and for beta 2,5: 6.28+or-0.2 eV. The spin-orbit split between 3p3/2 and 3p1/2 levels is found to be 1.67+or-0.05 eV, whereas the Hartree-Fock value is 2.24 eV.