MAGNETIC GROUND-STATE PROPERTIES AND SPECTRAL DISTRIBUTIONS .2. POLARIZED PHOTOEMISSION

Sum-rule-type results are derived to obtain orbital and spin magnetic moments from polarized core-level photoemission. The spin and orbital moments can be obtained from the first statistical moment of the spin spectrum and the circular dichroism, respectively. Analogous rules apply to all fundamental spectra. A simple diagram is given that shows what information is contained in the higher statistical moments. The core-valence exchange interactions are much simplified by rewriting them as couplings between the orbital moments and spins of the two shells. This allows, at the same time, a more precise treatment of intra-atomic coupling of magnetic moments. Valence-band photoemission is treated as a particle-hole analogue of x-ray absorption. The difference is the absence of a core hole with its interactions. The method of moments can be applied to both many-electron and one-electron theory, and illustrations are given for 3d and 4f systems. © 1994 The American Physical Society.