Determination of the crystal structure of the pi-AlFeMgSi phase using symmetry- and site-sensitive electron microscope techniques.
The crystal structure of the complex pi-AlFeMgSi phase, which was previously thought to have the composition Al(8)FeMg(3)Si(6), has been investigated. Microprobe analysis revealed that the phase has a different composition, Al(9)FeMg(3)Si(5). The space group was determined and confirmed to be P62m with the use of parallel-beam electron diffraction (SAD) and convergent-beam electron diffraction (CBED). Owing to symmetry considerations the elements within the unit cell had to be rearranged. The rearrangement was confirmed using electron channelling. The z parameters of the elements were refined by examining the intensities from high-angle convergent-beam electron diffraction. Finally, the x parameters were adjusted slightly to arrive at acceptable interatomic distances.
Foss
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Department of Physics, University of Oslo, PO Box 1048 Blindern, N-0316 Oslo, Norway. stefoss@fys.uio.no
Olsen
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A
Simensen
C J
CJ
Taftø
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