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Theoretical investigations of misfit dislocations in Pd/MgO(001) interfaces

2005; IOP Publishing; Volume: 17; Issue: 39 Linguagem: Inglês

10.1088/0953-8984/17/39/004

1361-648X

Yicheng Long, N X Chen, Hongyi Wang,

Microstructure and mechanical properties

This paper investigates the properties of dislocations in Pd/MgO(001) interfaces. By constructing ideal and virtual interface structures and applying the Chen–Mobius inversion method, we obtain interatomic potentials ΦPd–Mg and ΦPd–O directly from ab initio adhesive energies. Then, by applying the above potentials, as well as using the atomistic relaxation and molecular dynamics methods, stable interface structures are obtained. For simplicity, we use a two-dimensional model to provide some clear physical pictures of the dislocations. There are two kinds of mechanisms of dislocation formation: one is insertion of an extra slice of Pd atoms; the other is increasing the number of Pd layers, to produce dislocations via the increasing misfit stress. Finally, three-dimensional models are investigated, with dislocations perpendicularly intersecting in the interface. The calculated interfacial distances are in agreement with experiments.