Transmission electron microscopy investigation of Fe3O4 films grown on (111) Pt substrates

Thin Fe3O4 films prepared by iron deposition and subsequent oxidation on Pt (111) single crystal substrates were studied by selected area electron diff raction and high-resolution transmission electron microscopy (HRTEM). No ot her iron oxide phases were detected. The formation of Fe3O4 films takes pla ce epitaxially on Pt(111) substrates with the relationships: [111](Pt)/ /[1 11]Fe3O4, [1 (1) over bar0]Pt/ /[1 (1) over bar0]Fe3O4. The films were free of dislocations but contained antiphase boundaries (APB) between domains s hifted by 1.86 or 2.35 A relative to each other along the [111] direction. The lattice mismatch between Fe3O4 and Pt causes periodic arrays of straine d regions in the oxide along the interface. The iron oxide lattice paramete rs near the interface are compressed by approximately 2%. Detailed analysis of the Fe3O4/Pt interface based on HRTEM images and image simulations show that the first layer of the oxide on the Pt substrate consists of iron ato ms. (C) 2001 Elsevier Science B.V. All rights reserved.