The electronic structures of pyrite-type transition-metal chalcogenides MS2 - xSex (M = Fe, Co, Ni) has been investigated by photoemission and inverse-photoemission spectroscopy. The valence-band spectrum of ferromagnetic CoS2 does not show exchange splitting of the Co 3d peak, in disagreement with band-structure calculations. High-resolution photoemission spectra of NiS1.55Se0.45 shows spectral weight transfer from low (≃50 meV) to high (0.2-0.5 eV) binding energies, in going from the metallic to the insulating phase.
- Electronic structure
- Metal-insulator transition
- Photoemission spectroscopy
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering