A lattice-rectified and detection efficiency compensated APT reconstruction

Atom probe tomography (APT) provides a unique combination of highly chemically and spatially resolved 3D atomistic information. However, the technique has two significant constraints: limited detector efficiency and imperfect spatial resolution. Detector efficiency is inhibited by the open area of the microchannel plate (MCP), leading to upwards of 40% of the atoms evaporated from the specimen being omitted from the final analysis. This design limitation is common to all commercial detectors. The spatial resolution, although imperfect, is very high, however, this can be very much material and specimen dependent. Limited spatial resolution is due to a combination of trajectory aberrations caused by local geometric and compositional variations on the specimen, surface migration, preferential evaporation effects and the simplified geometry used in the 3D reconstruction [1]. Even with improved instrumentation, the burden of improving spatial resolution will mostly fall to the development of new and improved analytical approaches. This is a critical area of research, though, the current proportion of APT research efforts devoted to this objective is somewhat limited.