X-ray Photoemission Studies and Bonding in Amorphous Chalcogens.
Abstract
Trends in x-ray photoelectron (XPS) spectra of chalcogens which relate to their bonding are discussed. Valence band spectra of disordered S are reported along with measurements in the same apparatus of amorphous Se and Te. Each chalcogen's spectrum has a minimum about 7 eV below E(F), between the largely p-derived states nearer E(F) and the s-derived states. The p states are split into a largely non-bonding level near E(F) and a bonding peak an energy delta E(P) below it. The splitting delta E(P) (S, 3.5 eV; Se, 2.9 eV; Te, 2.2 eV) grows with decreasing atomic number, Z, and is found to scale with Pauling's bond energies. The s states exhibit an apparent bonding-antibonding splitting which grows with decreasing Z and scales with the increasing overlap of the s orbitals. Although the s states overlap, comparisons with calculated valence levels in the free atom suggest that most of the cohesive energy in the chalcogens is gained by the bonding of the p electrons, with no major contribution from the s electron.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 05, 1976
- Accession Number
- ADA028811
Entities
People
- Galen B. Fisher
- Richard B. Shalvoy
Organizations
- National Institute of Standards and Technology