9.2 ARPES: Holes, Nonbonding and Bonding States
187
Fig. 9.5 ARPES in 4° steps (in the parallel momenta k // ) shows the azimuth angular resolved DOS
for the clean Rh(001) (dotted curves) and Rh(001(2 × 2) p4g-O (solid curves) surfaces. The lines
between adjacent spectra resolve the dispersion due to O adsorption. Data were collected a along
M <10> direction and b along the X <11> direction [51]. Reprinted with permission from [51]
Rh(001) surface [51]. The PES spectra [51–53] showed that oxygen induces significant change in the energy states around −2 ~ −6 eV below E F . DOS for holes
below the E F can be resolved from the PES profiles of both phases [54]. Additional
O-derivatives can be identified at around −5 eV for the first (2 × 2)-O
− phase. The
feature around −5 eV shifts down a little with an additional peak at about −2.0 eV
at the same azimuth angles for the O
−2 -induced ‘p4g’ phase.
The ARPES in Fig. 9.6 shows that S chemisorption results in the similar valence
DOS for the O–Rh(001) surface. The similarity in the valence DOS identity suggests that the S may share the same 3sp-orbital hybridization creating the bonding,
nonbonding, holes, and antibonding states though they are subject to further confirmation. Therefore, the four valence DOS features seemed common for surfaces with
adsorption of electronegative elements having nonbonding lone pairs upon reaction.
187
Fig. 9.5 ARPES in 4° steps (in the parallel momenta k // ) shows the azimuth angular resolved DOS
for the clean Rh(001) (dotted curves) and Rh(001(2 × 2) p4g-O (solid curves) surfaces. The lines
between adjacent spectra resolve the dispersion due to O adsorption. Data were collected a along
M <10> direction and b along the X <11> direction [51]. Reprinted with permission from [51]
Rh(001) surface [51]. The PES spectra [51–53] showed that oxygen induces significant change in the energy states around −2 ~ −6 eV below E F . DOS for holes
below the E F can be resolved from the PES profiles of both phases [54]. Additional
O-derivatives can be identified at around −5 eV for the first (2 × 2)-O
− phase. The
feature around −5 eV shifts down a little with an additional peak at about −2.0 eV
at the same azimuth angles for the O
−2 -induced ‘p4g’ phase.
The ARPES in Fig. 9.6 shows that S chemisorption results in the similar valence
DOS for the O–Rh(001) surface. The similarity in the valence DOS identity suggests that the S may share the same 3sp-orbital hybridization creating the bonding,
nonbonding, holes, and antibonding states though they are subject to further confirmation. Therefore, the four valence DOS features seemed common for surfaces with
adsorption of electronegative elements having nonbonding lone pairs upon reaction.