Prakt. Met. Sonderband 38 (2006) 191 
The microstructure of the Ni-coating consisted of small grains. The size of the crystallites 
' FIB 10pA varies between 200nm and 2um. Both techniques (PECS™ and FIB) are suitable to reveal 
the microstructural features of the Ni-coating. SEM imaging of a specimen that was 
previous etched using PECS provides pictures with high sharpness and clearly defined 
boundaries. However, the better contrast (gray scale differences) was obtained when 
using FIB etching and visualization. The proper choice of the aperture (beam current) is of 
great importance. An excellent performance was achieved using 0.1 nA. From the other 
point of view it could be difficult to get a precise focus of the image when using currents 
higher then 10 pA. 
For the further consideration, the etching was performed at 0,3nA whereas imaging was 
done at 0.01 and 0,3nA. The results are shown in Figure 6, respectively. The use of the 
focused Ga-ions (rectangle 15x12mm) allowed revealing the microstructural features of Ni- 
coating. The appearance of the different etching features depends strongly on the aperture 
(current) using for the FIB imaging. 
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Ni-Coatin- Ann © Snatine 
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of the Ar’ 
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ly imaged. 
le of 45°, 
physically 
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ter Ar” ion — 
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Fig. 6: Microstructure of nickel coating after Ga” ion etching and FIB imaging, 0.01 nA 
“+ and 0,3nA aperture, resp. 
FIR 0 1nA 
To obtain a focused and a sharpened picture the use of the lower currents is 
recommended. The visualized structure is then similar to that after Ar® ion etching 
(PECS™ - Fig. 5). By increasing the current intensity, the contrast between the Ni-grains 
was enhanced. However, the quality (sharpness) became poor. Additionally, too high 
energy or excessive exposure time can damage the surface (see top of both pictures). 
4. SUMMARY 
PECS and FIB can be considered as complementary techniques for the revealing of 
microstructural features. The efficiency of the process depends strongly on the chemical 
and crystallographical composition of the material. Microstructural features of coatings and 
Zam materials containing Cu, Ag, or Ni (metals that have a face centred cubic crystallographical 
A (left 7 structure) are good resolved using FIB and PECS™ as well. Reported techniques can be 
considered to be complimentary with respect to the materials characterisation.