Role of regular steps on the formation of missing-row reconstructions: Oxygen chemisorption on Ni(771)

Scanning tunneling microscopy and LEED reveal that on regularly stepped Ni(771) the oxygen-driven missing-row reconstruction of the (110) terraces proceeds in a very transparent manner: Substrate atoms can move to adjacent terraces without crossing steps, where they line up with remaining atom rows to form linear O-Ni chains. On the resulting double-width terraces perfect missing-row structures all over the surface are formed in contrast to flat Ni(110); to surmount the double-step barrier, elevated temperatures ({≥}250 ^∘{}C) are required.