Atomic displacements of si in the si(111)-(3×3)R30°-ag surface studied by high-energy ion channeling

The atomic displacement of a Si(111) surface induced by Ag overlayers has been investigated by high-energy ion channeling. It has been found that (1) the $\sqrt{3}\times \sqrt{3}$ Ag surface has the vertical displacement of Si slightly larger than in the clean Si-7×7 surface, (2) the lateral displacement of Si is small and limited within a range of 0.13-0.3 Å, depending on the models proposed so far, and (3) the room-temperature Ag deposit significantly relaxes substantial vertical displacement of the 7×7 surface.