Core-level shifts on Be(101̄0)

A high-resolution photoemission study of the Be (1010) surface, at a sample temperature of 100 K, is reported. Three surface-shifted Be 1s components are revealed having shifts of -700, -500, and -220 meV. These are interpreted as originating from the first, second, and third plus fourth atomic layers while the bulk signal originates from the fifth and deeper layers. The surface layer shift for this more open Be(1010) surface is found to be smaller than for the close-packed Be(0001) surface. Reasons for this unusual behavior are suggested. © 1994 The American Physical Society.