Analytical Field Ion Microscopy

The predecessor of Ab initio simulations (APT), called the field ion microscopy (FIM) is known for its high spatial resolution, but at the expense of the chemical identity. To achieve improved spatial accuracy, data mining routines are developed here. Applying these routines, data extracted from a sequence of FIM images of W. The imaging distortions are analysed by comparing with atomistic and FIM image simulations, showing that the imaged atomic displacements are a consequence of the electrostatic field redistributions. To tackle the FIM's inability to discern between atoms of different chemical species, the development of a chemically-sensitive analytical FIM (aFIM) was developed. This technique is used to show the segregation of Re to a dislocation in a creep deformed Ni alloy.