The L 2:L 3 intensity ratio in soft X-ray emission spectra of 3d-metals

Abstract

We present L 2,3 X-ray emission spectra of the 3d-metals Ti through Cu. It is found that the ratio of the integrated non-resonant emission intensities of L 2 to L 3 emission, I(L 2)/ I(L 3), is approximately two times smaller than the ratio of the core hole state degeneracies (L 2/L 3 = 1/2). Our atomic calculations show that the L 2L 3M 4,5 Coster–Kronig transition is responsible for the reduction of the I(L 2)/ I(L 3) intensity ratio and explains its gradual decrease with increasing atomic number among the 3d transition metals. For the resonant case we find that accounting for the core–hole interaction and local field effects via TDDFT satisfactorily explains the changes in the I(L 2)/ I(L 3) ratio.