Self-assembling of potassium nanostructures on InAs(1 1 0) surface

Potassium induced one-dimensional nanostructures are formed by deposition on the InAs(1 1 0) surface held at about 420 K, as observed by scanning tunneling microscopy. The K adatoms self-aggregate in zigzag chains oriented along the [1 1̄ 0] direction even at very low coverage. By increasing the K density, the atomic chains pack together, though keeping a minimum distance of 18.2 Å. At the completion of the first layer, the nanostructures extend over the entire surface giving rise to a clear c(2 × 6) low energy electron diffraction pattern. At higher coverage, a second ordered overlayer is formed. The results are discussed in terms of recent theoretical calculations and experimental work on the model system of Cs chains self-assembled on the InAs(1 1 0) surface. The structural model proposed for a single chain is used to discuss the evolution of the overlayer structure as a function of coverage.