Ceramics - Sample Preparation for TEM

Application Note for Leica EM RES102 - Material Research

August 15, 2016

Problem
Ceramic samples are mostly very brittle, and are therefore very difficult to thin mechanically to a low starting thickness for ion beam milling.

The ion beam milling of insulators often leads to static charging of the surface of the sample. This, in turn, reduces the sputter rate. When using the Ti standard holder (standard TEM holder), however, sufficient secondary electrons are created by the ion beam also falling on the sample holder to largely compensate for the static charging.
The ceramics presented here are Al2O3 and ZrO2.

Preparation Conditions
Mechanical pre-preparation
TXP core drill to get a 3 mm disc.
TXP for double sided polishing down to a final thickness of 50 μm
Diamond foils: 6 μm, 3 μm, 1 μm and 0.5 μm at 2000 rpm.

Ion milling

Sample holder:Standard holder for TEM samples
Acceleration voltage:7 kV
Milling angle:6° (milling on both sides)
Sample movement:Rotation

Results
The illustrations show the grain structures of the two ceramic samples. The samples could be so very evenly and gently thinned, that even a high-resolution TEM examination was possible.

Download PDF

Fig.1: TEM image of an ion thinned ceramic sample (ZrO2)
Fig.2: TEM image of an ion thinned ceramic sample (ZrO2)
Fig.3: TEM image of an ion milled ceramic sample (Al2O3)
Fig.4: TEM image of an ion milled ceramic sample (Al2O3)

Comments