The electronic structure of stontium titanate from a direct transition analysis of angle resolved photoemission data

Angle-resolved photoemission spectra of SrTiO (100) have been recorded in the range 18eV⩽ hν⩽ 50eV. The results have been interpreted using a direct transition model and a free-electron like final state, yielding empirical Δ-line dispersion relations. While in overall agreement with available band structure calculations, significant discrepancies are revealed. In addition, resonance photoemission above the Ti 3p threshold has been used to identify regions of Ti 3d mixing in the mainly 0 2p valence bands, the results being consistent with theoretical models.