Self-assembly of iron nanoclusters on the Fe3O4(111) superstructured surface

TL;DR

This study demonstrates the self-assembly of iron nanoclusters into a regular array on a reconstructed magnetite surface, utilizing the surface's strain pattern as a template for controlled nanostructure growth.

Contribution

It introduces a method for growing ordered Fe nanoclusters on a nanopatterned Fe3O4(111) surface using strain-induced superstructure as a template.

Findings

Fe nanoclusters form a regular array matching the superstructure period

Initial Fe growth occurs in a two-dimensional mode

Random nucleation occurs outside the strain-patterned areas

Abstract

We report on the self-organized growth of a regular array of Fe nanoclusters on a nanopatterned magnetite surface. Under oxidizing preparation conditions the (111) surface of magnetite exhibits a regular superstructure with three-fold symmetry and a 42 A periodicity. This superstructure represents an oxygen terminated (111) surface, which is reconstructed to form a periodically strained surface. This strain patterned surface has been used as a template for the growth of an ultrathin metal film. A Fe film of 0.5 A thickness was deposited on the substrate at room temperature. Fe nanoclusters are formed on top of the surface superstructure creating a regular array with the period of the superstructure. We also demonstrate that at least the initial stage of Fe growth occurs in two-dimensional mode. In the areas of the surface where the strain pattern is not formed, random nucleation of Fe was observed.