Formation of a quasicrystalline Pb monolayer on the ten-fold surface of the decagonal Al-Ni-Co quasicrystal

TL;DR

This study demonstrates the formation of a well-ordered, quasiperiodic lead monolayer on a decagonal Al-Ni-Co quasicrystal surface, revealing insights into epitaxial growth and structural quality improvements upon annealing.

Contribution

It reports the first formation of a quasiperiodic Pb monolayer on a decagonal quasicrystal surface with detailed structural and electronic characterization.

Findings

Pb forms a well-ordered quasiperiodic monolayer

Annealing improves structural quality but causes evaporation and pore formation

Weak chemical interaction between Pb and substrate

Abstract

Lead has been deposited on the ten-fold surface of decagonal Al72Ni11Co17 to form an epitaxial quasicrystalline single-element monolayer. The overlayer grows through nucleation of nanometer-sized irregular islands and the coverage saturates at 1 ML. The overlayer is well-ordered quasiperiodically as evidenced by LEED and Fourier transforms of STM images. Annealing the film to 600 K improves the structural quality, but causes the evaporation of some material such that the film develops pores. Electronic structure measurements using X-ray photoemission spectroscopy indicate that the chemical interaction of the Pb atoms with the substrate is weak.