Growth Mechanism and Surface Alloy Formation of Ni on Pt(110)Surface

Low-energy electron diffraction (LEED) and Auger electron spectroscopy were used to observe the growth mode of a nickel thin film on a Pt(110)-(1×2) surface at room temperature. The Auger uptake curve of this system shows a premonolayer break and a monolayer break with an initial linear growth. The LEED pattern changes from (1×2) to (l×l) after half a monolayer of Ni is deposited on the substrate. The LEED pattern then shows a gradual diminishing of all spots when more layers of the Ni thin film are deposited on the Pt(110) surface. These results demonstrate that the initial growth of Ni on the Pt(110)-(1×2) surface follows the Stranski-Krastanov mode; growth of 1 1/2 monolayer followed by agglomeration into three-dimensional islands. The growth mechanism is discussed. A surface alloy film then forms by heating this surface at T—350 °C.