VISUALISATION AND ANALYSIS OF 3-DIMENSIONAL ATOM PROBE DATA

Abstract
A number of methods are outlined for the representation and analysis of 3-dimensional atom probe data yielded by the position-sensitive atom probe (POSAP). With the fast graphics capabilities of modem computers, atom positions or variations in composition within a specimen may be represented in three dimensions and manipulated in real-time. However it must be noted that the spatial information gained is affected by the nature of the field evaporation process, so that depth scaling, for example, must be carried out with some care. Some statistical analysis techniques currently used for conventional atom probe data can also be applied to the 3-dimensional data, which permits a useful degree of correlation between the two techniques. In addition, techniques for morphological analysis, such as measurements of connectivity and percolation, can also be applied. These methods, together with fractal techniques, may provide a size-independent means of parameterising the atomic-scale structures observed in the POSAP.