The β-FeSi2 was synthesized by heating mixtures of Si and Fe powder sealed with
Na metal and Ar gas in a stainless tube. Diffuse streaks elongated along the a axis
were observed in the electron diffraction patterns of β-FeSi2 prepared at 873K in
the Na melt. No streaks appeared on the spots indexed by k + l = 2n (n = integer),
which indicated existence of stacking faults caused by a slip system of
(100)[011]/2. The powder X-ray diffraction patterns of the samples prepared at
873K for 48h in the Na melt and at 1173K for 24h under reduced Na vapour
pressure were analyzed by using the Rietveld method together with a statistical
split-site model based uponon the stacking fault structure. The powder X-ray
diffraction patterns of the prepared samples: 48h the Na melt and at 1173K for 24h
in Na vapour which evaporated from a mixture of Na and Si were analyzed by the
Rietveld method with a statistical split-site model based on the stacking fault
structure. The ratios of the normal stacking layer and stacking fault layer of the
samples prepared at 873 and 1173K were estimated to be 0.95:0.05 and 0.84:0.16,
respectively. Main features of the observed powder X-ray diffraction patterns were
well reproduced by the calculation based on a general recursion method for
calculating diffracted intensities from crystals containing stacking fault.
Effects of Stacking Fault on the Diffraction Intensities of Β-FeSi2. H.Yamane,
T.Yamada: Journal of Alloys and Compounds, 2009, 476[1-2], 282-7