Abstract
The surface states on the LaB 6(100), (110) and (111) clean surfaces have been studied by means of angle-resolved UV photoelectron spectroscopy with unpolarized light. Surface states on LaB 6(110) and (111) have been observed for the first time, and the energy-band structures have been determined. The surface states on LaB 6(110) are located at ∼1.8 and ∼3.0 eV below E F. They are associated with the occurrence of the c(2 × 2) surface structure on LaB 6(110). The surface states on LaB 6(111) are located at ∼1.5 and ∼2 eV below E F. The dispersion of the lower band is relatively large (∼0.9 eV) compared with those on LaB 6(100) and (110). The surface state at ∼2 eV below E F on LaB 6(111) has a maximum energy at Γ point ( k∥ = 0), while that on LaB 6(100) has a minimum energy at Γ point. The surface state at ∼2 eV below E Fon LaB 6(100) possesses Δ 1 symmetry at k∥ = 0, and has even parity with respect to the (010) and (011) planes. The surface state at ∼1.8 eV below E F on LaB 6(110) has even parity with respect to the (11̄0) plane, and odd parity with respect to the (001) plane. The surface state at ∼3.0 eV below E F has even parity with respect to both the (11̄0) and (001) planes. The low-lying surface state on LaB 6(111) has Δ 1 symmetry at k∥ = 0. All these surface states on the LaB 6 clean surfaces are interpreted in terms of dangling bonds of the surface boron frameworks which are mainly B 2p in character.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call