Optimisation of specimen temperature and pulse fraction in atom probe microscopy experiments on a microalloyed steel

This paper details the effects of systematic changes to the experimental parameters for atom probe microscopy of microalloyed steels. We have used assessments of the signal-to-noise ratio (SNR), compositional measurements and field desorption images to establish the optimal instrumental parameters. These corresponded to probing at the lowest possible temperature (down to 20 K) with the highest possible pulse fraction (up to 30%). A steel containing a fine dispersion of solute atom clusters was used as an archetype to demonstrate the importance of running the atom probe at optimum conditions.

Research highlights► The optimal experimental conditions for running microalloyed steel specimens in atom probe was investigated and determined. ► The quality of experimental data is largely dependent on specimen temperature and less affected by pulse fraction. ► Temperatures as low as 20 K and pulse fractions up to 25% are the conditions for acquiring best quality data from microalloyed steels samples in atom probe.