Kinetics of oxygen-induced faceting of vicinal Ag(110)

Abstract

The oxygen-induced breakup of vicinal Ag(110) surfaces into (110) facets and step bunches is measured with scanning tunneling microscopy. Faceting transitions are recorded in real time at room temperature for two surface orientations. A vicinal Ag(110) surface misoriented by 2\ifmmode^\circ\else\textdegree\fi{} towards [001] facets via the growth of isolated nuclei. Step-position fluctuations of increasing magnitude are observed prior to faceting, revealing a critical terrace width of \ensuremath{\sim}100 \AA{}. In contrast, oxygen exposure causes Ag(110) misoriented by 2\ifmmode^\circ\else\textdegree\fi{} towards [33\ifmmode\bar\else\textasciimacron\fi{}1] to facet spontaneously with no evident nucleation barrier.