Electronic structure of graphitic boron at a TaB2(0001) surface

The electronic structure of the TaB2(0001) surface, which is terminated by graphitic boron layer has been investigated by angle-resolved ultraviolet p hotoelectron spectroscopy and first-principles self-consistent-charge discr ete variational-X alpha calculations. The occurrence of the charge transfer from Ta to B, leading to large work function (5.9 eV) of the TaB2(0001) su rface is confirmed from Mulliken population analysis. It is concluded that the graphitic boron layer at the TaB2(0001) surface forms pi bond, which is largely modified due to hybridization with the Ta 5d orbitals. [S0163-1829 (99)03328-7].