CRYSTALLINE SYMMETRY EFFECTS IN X-RAY MAGNETIC CIRCULAR-DICHROISM IN ANGLE-RESOLVED CORE-LEVEL PHOTOEMISSION

The dependence of magnetic circular dichroism (MCD) in core-level photoemission on the experimental geometry and direction of electron emission has been studied experimentally using photoemission from the 2p and 3p levels of iron. The MCD has been measured both along emission directions of high symmetry, and along general emission directions within a single mirror plane. The observed angular variations cannot be accounted for by model calculations based on absorption, or based on angle-resolved emission into photoelectron states of a single, oriented atom. They are consistent with a model where the photoelectron states of the crystalline symmetry appropriate to couple to the detector are used.