Structure and growth of Mn on Cu(100)

Abstract

The structure and growth of manganese on Cu(100) was studied using Auger electron spectroscopy (AES), low energy electron diffraction (LEED) and medium energy electron diffraction (MEED). Depending upon the film thickness and the sample temperature during deposition a variety of superstructures is observed. At growth temperatures below 270 K the first Mn layer wets the Cu substrate and grows in a c(8 × 2) structure with hexagonal atomic arrangement. Above 1 ML Mn, the films become increasingly more disordered and rearrange into a c(12 × 8) structure. Manganese is incorporated into the surface above 270 K. This leads to the formation of two ordered surface alloys at growth temperatures above 270 K: a c(2 × 2) structure around 0.5 ML Mn and a p2mg(4 × 2) structure above 1 ML Mn. Irreversible phase transitions upon annealing have been studied for the low temperature structures. This confirms that incorporation of Mn is the essential step to form the ordered surface alloys.