Spontaneous growth of Ag and Pb nanopucks on electronic patterns of 2D Pb quantum islands

Two-dimensional ordered Ag and Pb nanopuck arrays have been grown on two different types of Pb quantum islands. Electronic patterns on the surfaces of Pb islands serve as the templates for the growth. Nanopucks of different materials display dissimilar growth behaviors, reflecting the varied interaction strength between adatoms and the substrate. Due to a strong interaction existing between Ag atoms and the substrate, perfectly ordered Ag nanopucks of nearly identical size can be fabricated. The Ag array can sustain a wide growth temperature range from 70 K to 150 K, while for Pb nanopucks, the similar result can be obtained only below 70 K. The stronger interaction also synchronizes the behavior of Ag nanopucks with that of the Pb island substrate, which exhibits a bilayer alternating character.