Final-state magnetic dichroism in Fe 3s photoemission.

Abstract

Magnetic dichroism measurements using unpolarized Mg${\mathit{K}}_{\mathrm{\ensuremath{\alpha}}}$ radiation are reported for Fe 3s and 2s x-ray photoemission from ferromagnetic Fe. The Fe 3s level displays a small magnetic dichroism, whereas any dichroism present in the Fe 2s level is too small to be reliably detected. Since the Fe 3s level does not experience an initial-state spin-orbit interaction, these results reveal the existence of a final-state magnetic dichroism in photoemission. Two possible sources of the dichroism are discussed. The first explanation invokes a combination of the Fano effect and core-valence exchange to introduce magnetic dichroism into the 3s photoemission. An alternative explanation explores the possibility that configuration interaction in the 3s hole state introduces 3${\mathit{p}}^{4}$ hole character into the 3s photoemission, with Fe 3p spin-orbit coupling providing the dichroic behavior. Further theoretical and experimental work is needed to definitively assign the origin of the observed magnetic dichroism in Fe 3s photoemission. \textcopyright{} 1996 The American Physical Society.