(10x2) strained reconstruction induced by oxygen adsorption on the Rh(110)surface

Oxygen adsorption on the (1x2) missing row reconstructed Rh(110) surface ha s been studied by means of low-energy electron diffraction (LEED), x-ray ph otoelectron spectroscopy (XPS), and scanning tunneling microscopy (STM). St arting from the already known (2x2)p2mg oxygen overlayer in which the subst rate is (1x2) reconstructed, further oxygen has been dosed at room and lowe r temperatures. Upon heating, additional substrate reconstruction takes pla ce and the surface forms a new structure with (10x2) periodicity and high l ocal oxygen coverage. Oxygen 1s XPS measurements show a binding energy shif t from 530.25 eV in the (2x2)p2mg to 529.75 eV in the (10x2) layer. Analysi s of STM images reveals that in the (10x2) layer, the rhodium close-packed rows are strained and segmented in the [1 (1) over bar0] direction. On the basis of the experimental results, models for the (10x2) structure and its formation process are proposed and compared with "pseudo-oxide" structures. (C) 2001 American Institute of Physics.