Thermal effects on mass and spatial resolution during laser pulse atom probe tomography of cerium oxide

Cerium oxide (CeO2) is an ideal surrogate material for trans-uranic elements and fission products found in nuclear fuels due to similarities in their thermal properties; therefore, cerium oxide was used to determine the best run condition for atom probe tomography (APT) of nuclear fuels. Laser-assisted APT is a technique that allows for spatial resolution in the nm scale and isotopic/elemental chemical identification. A systematic study of the impact of laser pulse energy and specimen base temperature on the mass resolution, measurement of stoichiometry, multiple detector hits, and evaporation mechanisms are reported in this paper. It was demonstrated that using laser-assisted APT stoichiometric field evaporation of cerium oxide was achieved at 1 pJ laser pulse energy and 20 K specimen base temperature.