A study of the iron borides. III. Multiplet splitting in ESCA Fe 3s

Abstract
The multiplet splitting of the X-ray photoemission (ESCA) Fe 3s core levels of the ferromagnetic iron borides, FeB and Fe2B is discussed. It is shown that the observed multiplet splitting is larger than that expected from calibration with the magnetic moments of highly ionic compounds. This is interpreted by the operation of minority spin correlation in the metallic iron borides, which affects the high spin states and thereby increases the experimental splitting. This effect is due to the itinerant d electrons, and it is suggested that these electrons must be considered in order to understand ESCA multiplet splitting in many metals and alloys.