Angle-resolved photoemission study ofSrTiO3(100) and (110) surfaces

Angle-resolved photoemission spectra of ${\mathrm{SrTiO}}_3$ (100) and (110) surfaces have been obtained. The normal-emission data are analyzed using the direct transition model and, as a result, the valence band is determined along the Δ and Σ lines in the bulk Brillouin zone. The empirical valence-band structure is found to be consistent with the band calculations if and only if proper magnitude of the O 2p crystal-field splitting is adopted. The effect of the O 2p crystal-field splitting on the band structure is discussed. © 1996 The American Physical Society.