Host: The Japan Society of Vacuum and Surface Science
We will put more focus on the effect of competitive surface-site occupation between carbon and other surface-active impurities on single-layer graphene (SLG) growth. It is known that sulfur is a typical impurity of metals and the most surface-active element. The surface sites are finally occupied by sulfur at the elevated temperatures by surface segregation. In the case of Ni(110) surface, it is confirmed by scanning Auger microscopy, LEEM and STM that the available surface sites are nearly occupied by sulfur with a centered 2x2 arrangement. When the Ni(110) is doped with carbon, surface segregation of carbon shall be strongly affected by such a surface-active element. In this situation, we discovered a strongly directional growth of SLG, exhibiting a square-like shape. The detailed characterization at the nanoscale and interesting growth mechanism shall be discussed.
