CONTRIBUTION OF 3D ATOM-PROBE TO THE UNDERSTANDING OF PLANE-BY-PLANE AP ANALYSES DATA - APPLICATION TO THE STUDY OF ORDERING IN CU3AU

3D atom probes such as the tomographic atom probe, make it is possible to perform plane-by-plane analyses with a very large field of view. A s in the case of the conventional atom probe, these analyses are subje cted to a number of possible artefacts such as preferential retention or evaporation of species, or pile-up effects. However, taking advanta ge of the use of a position-sensitive detector, it is possible to stud y where these artefacts preferentially occur within the area of analys is. Then, experimental conditions can be selected in order to minimise the spatial extent of these artefacts. We have developed new programs in order to get a better understanding of the field evaporation behav iour of planes. We have shown that it is possible to considerably mini mise artefacts by carefully setting the tip temperature, These results have been applied to the study of ordering phenomena in Cu3Au with th e tomographic atom probe.