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Application Note for Leica EM RES102 – 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.