Field ion microscopists demonstrated more than twenty years ago that polarizable atoms adsorbed on a stepped surface can be induced to diffuse by an electric field due to the field gradients associated with step edges. We have exploited a similar phenomenon, the large field gradients in the vicinity of the STM tip, to induce the directional diffusion of Cs and K atoms adsorbed on room temperature GaAs(110) and InSb(110). The geometric and electronic properties of both the naturally occuring and electric field-induced alkali metal structures observed on these semiconductor surfaces are discussed, including the possibility that the alkali metal overlayers are Mott insulators.
Conference Dates: August 17, 1992
Conference Location: Ventura, CA
Conference Title: Atomic and Nanoscale Modification of Materials: Fundamentals and Applications
Pub Type: Conferences