Electron-yield saturation effects in L-edge x-ray magnetic circular dichroism spectra of Fe, Co, and Ni

Saturation effects are determined in x-ray magnetic circular dichroism spectra, acquired by electron yield techniques. It is shown that sum-rule extraction of the number of d holes, orbital moment, and spin moment are affected for Fe, Co, and Ni. In particular, errors in the extracted orbital moment values due to saturation effects can be in excess of 100% and even yield the wrong sign for films as thin as 50 Angstrom. They are significant even for film thicknesses of a few monolayers. Errors for the derived values for the number of d holes and the spin moment are considerably smaller but may be of the order 10-20 %. Correction factors are given for quantities obtained from sum rule analysis of electron yield data of Fe, Co, and Ni as a function of film thickness and x-ray incidence angle. [S0163-1829(99)01009-7].