Structural characterization of Fe(1 1 0) islands grown on α-Al2O3(0 0 0 1)

Abstract

The morphology, size distribution, epitaxial relationships and lattice distortion in nanometer sized Fe(1 1 0) oriented islands grown on Al2O3(0 0 0 1) are studied and discussed as a function of the amount of deposited Fe. Combined scanning electron microscopy and transmission electron microscopy (TEM) as well as atomic force microscopy measurements show the dependence of these parameters with island size. For the smallest island sizes, an iron lattice distortion with respect to bulk values is found at their edges. Electron energy loss spectroscopy experiments demonstrate the absence of oxidation of the Fe islands either due to the high temperature deposition on Al2O3 or to the polishing procedure prior to TEM observations. From the analysis of the relative intensity for the L2 and L3 Fe peaks, a high spin ground state for the Fe atoms is deduced, probably correlated with the highly distorted regions at the edges of the islands. © 2003 Elsevier Science B.V. All rights reserved.