The two-dimensional oxygen-induced energy bands of the Cu(110)/2 x 1-O
surface were investigated by angle-resolved ultraviolet photoemission
spectroscopy (ARUPS). A new finding in the present report is that the
oxygen-derived O 2p(y) and O 2p(z) bands cross and hybridize between
<(Gamma)over bar> and (Y) over bar along the [001] direction. A fight-
binding band calculation assuming the missing-row reconstruction model
was successfully made to reproduce the dispersion of the oxygen-deriv
ed bands, including band crossing as well as symmetry characteristics.
An ARUPS study on a surface with a very small amount of adsorbed oxyg
en of about 0.01 ML was also made, An interesting result is that almos
t the same dispersion as that of the well-ordered 2 X 1-O surface of 0
.5 ML is observed, This result indicates that Cu-O chains directed alo
ng the [001] direction grow long enough to apparently give the same di
spersion, even in the initial stage of oxygen adsorption.