Chemistry Reference
In-Depth Information
Fig. 5.10
HRTEM image of a
region of a Ni catalysed wire
with planar defects
Fig. 5.11
TEM- HAADF
image of the region near to
the tip. In this technique,
called also z-contrast, high
atomic number elements are
highlighted by a lighter
colour. In this case the tip is
much brighter than the rest of
the nanowire because it
contains nickel (Z
=
28)
instead of silicon (Z
=
14)
and carbon (Z
=
6)
TEM analysis (Fig.
5.10
) shows a 3-C SiC structure with
<
111
>
axis along the
growth direction. Along the wire, it is possible to spot wide areas of good crystalline
quality alongside of zones with stacking defects on (111) planes.
High Angle Annular Dark Field (HAADF) STEM Tomography (Fig.
5.11
) high-
light a particle on the tip of the nanowires. In the image the bright colour indicates
the presence of high atomic number elements, in this case nickel, clue of a VLS type
growth.
