Growth of Au Particles Evaporated on KBr and KCl Substrates Wearing Increased Densities of Surface Steps

抄録

  Growth forms of Au particles prepared by vacuum evaporation methods on KBr(001) and KCl(001) substrates with two types of surface steps prepared by thermal sublimation and by electron stimulated desorption are studied by using a carbon backing method with a transmission electron microscope. Spiral steps of monoatomic height have been prepared on the substrate surfaces by heat sublimation. Epitaxial Au particles with pyramidal shapes and other multiply twined particles are grown by the vacuum evaporation on the substrates at temperatures of 50-450℃. The size distributions of the particles on the substrates are reported and the typical size is measured to be smaller than 20×20 nm². The ratio of populations of the multiply twined particles along the KBr steps is increased compared with that on the flat area. However, this increase in the ratio is not observed for particles grown on KCl. Additionally, step assemblies are prepared by electron stimulated desorption (ESD). The dependence of the size distributions of the Au particles grown on the substrates on electron fluence is measured for the ESD surfaces. With increasing electron fluence, the peak particle distribution size becomes smaller and particles smaller than 1 nm are observed.