title: Strain relief of heteroepitaxial bcc-Fe(001) films.
abstract: The strain relief of heteroepitaxial bcc-Fe(001) films, deposited at 520-570 K onto MgO(001), has been investigated by scanning tunneling microscopy. In accordance with real-time stress measurements, the tensile misfit strain is relieved during coalescence of flat, mainly 2-3 monolayers (ML) high Fe islands at the high thickness of approximately 20 ML. To accommodate the misfit between merging strain-relaxed islands, a network of 1/2[111] screw dislocations is formed. A strong barrier for dislocation glide--which is typical for bcc metals--is most likely responsible for the big delay in strain relief of Fe/MgO(001), since only the elastic energy of the uppermost layer(s) is available for the formation of an energy-costly intermediate layer.
authors.affiliation: Research Centre Jülich, Institute of Solid State Research, Electronic Properties, D-52425 Jülich, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Wedler
authors.forename: C M
authors.initials: CM
authors.lastname: Schneider
authors.forename: A
authors.initials: A
authors.lastname: Trampert
authors.forename: R
authors.initials: R
authors.lastname: Koch