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Analysis of Al adatoms random hopping on Si(100)-c(4 x 2) surface observed by STM at low temperature: Determination of the hopping barriers

Publikace na Matematicko-fyzikální fakulta |
2022

Tento text není v aktuálním jazyce dostupný. Zobrazuje se verze "en".Abstrakt

Mobility of single aluminium atoms adsorbed on Si(100)-c(4 x 2) surface was studied by means of scanning tunneling microscopy (STM) at a temperature of 115 K. Due to a strongly anisotropic surface migration along silicon dimer rows the hopping in one-dimensional (1-D) bounded areas of various sizes was observed.

Distributions of distances traversed in a time between acquisition of two subsequent STM images were obtained. The experimental conditions were interpreted by a model of 1-D random walk of Al adatoms in areas of limited size with reflective boundaries.

Kinetic Monte Carlo (KMC) simulations were used for analysing dependence of a calculated activation energy for a single hop on a size of the 1-D bounded area. The developed method allowed restoration of a real value of the activation energy for the Al adatom hopping in a direction parallel to the silicon dimer rows unaffected by the limited size of the bounded area.

The activation energy for hops in a direction perpendicular to the dimer rows was estimated from a distribution of time intervals between individual perpendicular hops.