Periodic array of misfit dislocations at the MnAs/GaAs interface studied by synchrotron x-ray diffraction
- Paul-Drude-Institut fuer Festkoerperelektronik, Hausvogteiplatz 5-7, D-10117 Berlin (Germany)
We study the evolution of strain, morphology and interfacial structure during the growth at 250 deg. C and subsequent annealing of MnAs films on GaAs in situ using grazing incidence x-ray diffraction. The MnAs film grows via the formation of relaxed islands which increase in size and finally coalesce to form a continuous film. Early on, an ordered array of misfit dislocations forms at the interface with a spacing of 4.95{+-}0.05 nm, releasing the misfit strain. The Burgers vector of the dislocations lies in the interface plane, and the inhomogeneous strain due to the dislocations is confined to a 1.6 nm thick region near the interface. Annealing enhances the order of the dislocation array and reduces the mosaicity of the MnAs layer. On MnAs/GaAs(113)A, the same mismatch is released by the dislocations with the two times smaller Burgers vectors and the two times smaller spacing, as compared with the MnAs/GaAs(001)
- OSTI ID:
- 20719631
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 72, Issue 15; Other Information: DOI: 10.1103/PhysRevB.72.155303; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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