Metastable misfit-induced relaxation structures of close-packed heteroepitaxial films
1998; Elsevier BV; Volume: 401; Issue: 3 Linguagem: Inglês
10.1016/s0039-6028(98)00049-1
ISSN1879-2758
AutoresK. Meinel, H. Wolter, Ch. Ammer, H. Neddermeyer,
Tópico(s)Magnetic properties of thin films
ResumoAbstract Conventional and O-mediated Cu film growth on Ru(0001) is studied by means of STM and LEED at temperatures between 300 and 550 K. At temperatures above 500 K and for a Cu film thickness above three monolayers, misfit-induced strain is almost completely released via a slight rotation of the film lattice inducing a stable moire-like reconstruction. At lower temperatures, two metastable relaxation structures are observed belonging to a non-rotated and slightly strained Cu film. In cases where the relaxation proceeds more locally, a tile-like honeycomb pattern of domains aligned along [112]-like directions is developed (unit mesh 60 A). Large-scale relaxation gives rise to a hexagonal pattern of triangular domains (side length 25 A) aligned along [110]-like directions (unit mesh 64 A). In both structures energetically unfavorable on-top positions are avoided by forming domain boundaries and dislocations. The structures are elucidated by simple hard-sphere models.
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