Using Detection Efficiency as an Indicator of Losses During Atom Probe Tomography Analysis of Oxygen-Rich Materials.

Atom probe tomography (APT) enables atomic-scale compositional analysis in a wide range of materials; however, quantification in oxygen-rich materials remains challenging due to apparent oxygen losses during analysis. We present here a correlative method, combining transmission electron microscopy and analytical or numerical modeling, to estimate the APT analyzed volume and detection efficiency. Applied to CePO4 samples, the approach revealed that increasing laser pulse energy reduces detection efficiency, likely through enhanced neutral desorption. Analysis on pure aluminum confirmed the robustness of the method, while highlighting limitations in accurately determining the evaporated depth and compositional uncertainties. The results demonstrate consistent qualitative trends with known oxygen loss mechanisms in synthetic monazites. This work provides a foundation for developing a method to better understand the loss of neutral species during field evaporation and consequently the compositional biases observed in APT analyses. By linking morphological measurements with modeling of the analyzed volume, it opens the way to a more accurate interpretation of detection efficiency variations and elemental deficiencies in oxygen-rich materials.