Volume determination of TEM specimens containing particles or precipitates.

The volume of thin foil specimens, which contain precipitate or other particles, viewed in the TEM is needed to determine particle density and spacing. It can be determined from the locations of the particles, measured using stereo pairs. A calculation that determines the volume between planes (not necessarily parallel or horizontal) that enclose the points is described. These planes will systematically underestimate the actual surface spacing and hence the volume, but a simple correction factor based on the number of points used in the fit can be used to estimate the actual volume. The method is tested, and its accuracy is evaluated using simulated data and applied to precipitate particles in creep-tested silicon carbide.