First-principles study of the (0 0 1) surface of cubic BiAlO3

The BiO and AlO2 terminations have been constructed for the BiAlO3 (0 0 1) surface. The cleavage and surface energies, surface relaxation and surface electronic structure have been calculated for the two types of (0 0 1) terminations using first principle plane waves ultrasoft pseudopotential method based on local density approximation. The results show that compared with the BiO termination, the AlO2 termination corresponds to the lower surface energies and is more easily constructed. For the BiO termination, some states in the conduction band are remarkably lowered and pulled down in the band gap region; however, for the AlO2 termination the valence band exhibits an upward shift, intruding into the lower part of the band gap, especially at the M point.