Comparisons of Techniques - Sample Preparation Topic for Transmission Electron Microscopy - page 212

Fig. 8.21 Dark-field,
higher-magnification image
of the same material, showing
that the hydroxyapatite is a
mixture of amorphous and
crystalline material. The FIB
technique did not enable
producing slices thin enough
for HRTEM observations.
( M. Iliescu, J. Werckmann
IPCMS Strasbourg )
Fig. 8.22 The material is
thinned using the tripod
polishing technique, and a
cross section of the
HA/TiN/Si material is
obtained (the Si substrate is
not visible here). Only a fine
layer of HA in contact with
TiN (which is opaque) is kept,
a large part of the material
was torn away during the
mechanical polishing.
However, the surface (a) is
well preserved and appears
flat, and despite the damage
from irradiation, observation
in HRTEM is possible.
( M. Iliescu, J. Werckmann
IPCMS Strasbourg )
FIB can thin down very brittle materials to obtain large observable areas, but
with poor resolution. Conversely, the tripod polishing technique enables HRTEM
investigations, but only on very small areas, with the risk of material losses through
tearing. Both techniques are complementary.
Tripod Polishing Technique + Ion Milling (“Techniques” Chapter 4, Section 3;
“Techniques” Chapter 3, Section 5) and FIB Thinning Techniques
(“Techniques” Chapter 3, Section 6)
Bulk material: Cross section of a metallic superconductor with Nb 3 Sn filaments
in a bronze matrix