Valence-band structure of TiO₂ along the Γ∑M line

Angle-resolved photoemission spectra of rutile TiO₂(1 1 0) have been recorded using synchrotron radiation. The dispersions of the bulk valence bands, which are mainly O 2p in origin, are mapped along the Σ-line of the bulk Brillouin zone using the direct transition model and a free-electron-like final state. Polarisation selection rules are used to distinguish between the Σ₁ and Σ₂ components of the initial-state valence bands. The five experimentally observed bands are compared with a bulk band structure calculated using an ab initio method within the Local-Density-Approximation. We find good agreement between the calculated and experimental bands.