Atomic-Level Simulations of Misfit Dislocation at the Interface of Fe2O3/Al2O3 System

Journal Article · Fri May 16 04:00:00 EDT 2003 · Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms

DOI:https://doi.org/10.1016/S0168-583X(03)00523-8· OSTI ID:15005570

Gao, Fei ^[1]; Wang, Chongmin ^[1]; Maheswaran, Saravanamuthu ^[2]; Thevuthasan, Theva ^[1]

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1. BATTELLE (PACIFIC NW LAB)
2. University of Western Sydney

When -Fe2O3 thin films are deposited on -Al2O3 (0001) substrates using oxygen plasma assisted molecular beam epitaxy (OPA-MBE), a periodic distribution of basal dislocations occurs due to lattice mismatch along the interfaces. High-resolution transmission electron microscopy (HRTEM) shows, when observed from zone axis, that these dislocations lie at the interface about 7.0 nm apart. Molecular dynamics simulations (MD) were performed in order to understand the formation of misfit dislocations and the interface structural features in Fe2O3/Al2O3 system. It is found that the misfit dislocations are mainly formed in Al2O3 substrates with Burger's vector of 1/3, and terminated at the interfaces, in consistent with experimental observations. These dislocations can dissociate into two partial dislocations with Burger's vectors of 1/3 and 1/3 by forming stacking faults on (0001) planes. The core structures of the misfit dislocations in semicoherent interfaces are analyzed in detail, and the misfit dislocations narrow cores in the plane of the interfaces.

• Research Organization: Pacific Northwest National Lab., Richland, WA (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 15005570
• Report Number(s): PNNL-SA-36447; KC0201020
• Journal Information: Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms, Journal Name: Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms Journal Issue: 1 Vol. 207
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPUTER SIMULATION
DISLOCATIONS
DISTRIBUTION
EPITAXY
INTERFACE
MISFIT DISLOCATION
MOLECULAR BEAM EPITAXY
OXYGEN
PLASMA
STACKING FAULTS
SUBSTRATES
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
VECTORS