Towards Quantitative EDX Results in 3 Dimensions

In principle, energy dispersive X-ray (EDX) mapping can be combined with electron tomography since the number of generated X-rays scales linearly with sample thickness. However, early attempts to perform 3D EDX experiments were complicated by the specimen-detector geometry [5]. Therefore, recent efforts lead to a novel design of the EDX detector system, which enables one to apply 3D EDX mapping to different structures [6]. An example of a 3D EDX reconstruction, obtained using 2D EDX maps that have been acquired using a probe corrected Titan, equipped with a Super-X system is presented in Figure 1. The reconstruction shows a Au@Ag nanocube of which the Au core yields an octahedral shape [7]. This example clearly illustrates the potential of 3D EDX mapping, but one needs to be careful when extracting quantitative information from such reconstructions. To reach this goal, the different steps of an EDX tomography experiment need to be optimized.