3-dimensional reconstruction from a sequential set of focus ion beam milled 2-dimensional cross-sections

The use of a focused ion beam system to mill a set of sequential 2-dimensional cross-sections which can be used for 3-dimensional reconstruction is outlined. To illustrate the technique the 3-dimensional shape of a surface grain in a 1 mum thick aluminium film, and a subsurface grain in a FeAl nanocomposite have been reconstructed. A grain is selected and the co-ordinates of its grain boundary in each 2-dimensional cross-section are determined. This information is then used to reconstruct the 3-dimensional shape of the grain. To assess the technique, the shape of the grain boundary at the surface of a selected grain in the thin film (taken before FIB sectioning) has been compared to its reconstructed shape. The application of the technique to other systems, its limitations and automation are discussed.