Periodic faceting on TaC(110): Observations using high-resolution low-energy electron diffraction and scanning tunneling microscopy

Unidirectional alternating (100)-(010) faceting has been observed for the clean TaC(110) surface using both high-resolution low-energy electron diffraction and scanning tunneling microscopy. Facets propagate periodically along the [11̄0] direction and form a ridge-and-valley grating, characterized by an average periodicity of ∼6 lattice spacings in the [11̄0] direction, where (110) terraces are completely absent. This faceted surface is shown to be an energetically favored structure.