On the thermal stability of thin Cu overlayers on Ni (111)

Abstract
The stability against heating of thin Cu overlayers (up to four monolayers, θ ≤ 4) on Ni(111) has been studied with ultraviolet photoelectron spectroscopy (hv = 21.2 eV) and LEED. A comparison is made of the stabilities of one monolayer and of the thin overlayer (θ ≃ 1.5–2) left on the substrate after Cu agglomeration induced at θ = 4 by treatment at 450°C. This last overlayer involved also in the Stranski–Krastanov growth is much more stable than one monolayer; we discuss the role of the clusters in this effect.