The atom-probe field ion microscope (APFIM) is capable of obtaining both microstructural and chemical information from a sample on an atomistic scale not accessible by any other technique. A schematic is shown. The sample is in the form of a sharp tip which has been electrochemically polished to an end radius of 100-1000 A. After cooling the sample to 25 K by a closed-cycle refrigeration system, pressure in the field ion microscope (FIM) chamber is in the 10** minus **1**1 torr range. Image resolution of the FIM is on the order of a few A and surface atoms are imaged. Mass resolution of the atom-probe is better than 1000, which is more than sufficient to resolve metal isotopes and their hydrides. Detectability is close to the theoretical limit, which is determined mainly by the efficiency (55%) of the channel plate detector.
|Number of pages||3|
|Journal||Proceedings, Annual Conference - Microbeam Analysis Society|
|Publication status||Published - 1984 Dec 1|
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