Spin-resolved APS for K-, L- and M-line emissions of Ni

Appearance potential spectroscopy (APS) spectra are measured near Is, 2p an d 3p core electron excitation energies for ferromagnetic Ni with spin polar ized electrons. Spin resolved spectra for Ni 2p(3/2) were explained by a on e-electron approximation with parameterized Anger matrix elements. Though t he aspects of spin integrated spectra for 2p(1/2), are very similar to thos e for 2p(3/2), our spin resolved spectra cannot be explained by the above a pproximation. The spectra for Is were measured for K alpha characteristic X -ray energy region. Nevertheless they do not show a clear variation of the primary electron spin dependence near Is appearance potential. The spectra for 3p show an entirely different aspect from those for 2p. This may be cau sed by the many body effect for which the soft X-ray emission intensity is resonantly enhanced (i.e. resonant inverse photoemission). (C) 2001 Elsevie r Science B.V. All rights reserved.