In:
Microscopy and Microanalysis, Oxford University Press (OUP), Vol. 19, No. 5 ( 2013-10), p. 1298-1302
Abstract:
Structures comprising single-crystal, iron-carbon-based nanowires encapsulated by multiwall carbon nanotubes self-organize on inert substrates exposed to the products of ferrocene pyrolysis at high temperature. The most commonly observed encapsulated phases are Fe 3 C, α-Fe, and γ-Fe. The observation of anomalously long-period lattice spacings in these nanowires has caused confusion since reflections from lattice spacings of ≥0.4 nm are kinematically forbidden for Fe 3 C, most of the rarely observed, less stable carbides, α-Fe, and γ-Fe. Through high-resolution electron microscopy, selective area electron diffraction, and electron energy loss spectroscopy we demonstrate that the observed long-period lattice spacings of 0.49, 0.66, and 0.44 nm correspond to reflections from the (100), (010), and (001) planes of orthorhombic Fe 3 C (space group Pnma ). Observation of these forbidden reflections results from dynamic scattering of the incident beam as first observed in bulk Fe 3 C crystals. With small amounts of beam tilt these reflections can have significant intensities for crystals containing glide planes such as Fe 3 C with space groups Pnma or Pbmn .
Type of Medium:
Online Resource
ISSN:
1431-9276
,
1435-8115
DOI:
10.1017/S1431927613001918
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
2013
detail.hit.zdb_id:
1481716-0
SSG:
11
SSG:
12
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