Abstract
Low-energy-electron-diffraction (LEED) and angle-resolved inverse photoemission spectroscopy (ARIPES) have been applied to the cleaved surface of single crystals. The LEED pattern shows a surface lattice which is identical to the superlattice found in the bulk structure. ARIPES along the ΓX() direction yields nondispersive unoccupied electronic states at 2.9 and ∼5 eV above the Fermi energy attributed to Bi-O derived conduction bands. At 0.47 ΓX the experimental density of states at the Fermi level increases. This may be due to the crossing of the O(1) band through derived from oxygen atoms in the Cu-O planes.
- Received 28 December 1988
DOI:https://doi.org/10.1103/PhysRevB.39.7316
©1989 American Physical Society