Spin-resolved and high-energy-resolution x-ray photoelectron spectroscopy (XPS) measurements of the 3s and 2s levels of metallic cobalt are reported. The high-resolution 3s spectrum shows a multiplet splitting Δ${\mathit{E}}_{3\mathit{s}}$ of 3.3±0.3 eV. The metallic value and literature Δ${\mathit{E}}_{3\mathit{s}}$ values for ${\mathrm{CoF}}_2$ and ${\mathrm{CoF}}_3$ display a linear variation with (2S+1) in accord with the Van Vleck model. This finding, combined with the absence of core-level XPS satellites in Co metal attributable to localized final-state 3d charge fluctuations, implies that intra-atomic exchange dominates the Co 3s spectrum, and indicates that the creation of a core hole does not alter the 3d electron population in metallic Co, ${\mathrm{CoF}}_2$, or ${\mathrm{CoF}}_3$. The large role played by intra-atomic exchange is explicitly revealed by spin-resolved XPS (SRXPS) investigation of the Co 3s level. The SRXPS data show a predominantly minority-spin character for the main (low-binding-energy) 3s component, and a strong majority-spin character for the smaller 3s component at higher binding energy. Although high-resolution Co 2s XPS measurements give no indication of multiplet structure, SRXPS Co 2s measurements reveal a 0.65±0.3 eV exchange splitting between majority-spin and minority-spin components, as well as a significant spin dependence to the ${\mathit{L}}_1$${\mathit{L}}_{2,3}$${\mathit{M}}_{4,5}$ Coster-Kronig transition probability.

• Received 26 July 1993

DOI:https://doi.org/10.1103/PhysRevB.49.2040