Reviewing the Experimental Estimation of the Laser-Induced Apex Temperature in Atom Probe Tomography and Application...

Determining the laser-induced specimen apex temperature in atom probe tomography is fundamental to understanding and ensuring analytical accuracy and reliability. This study reviews the existing protocols and assesses their applicability to experimentally determine the apex temperature rise of silicon specimens under ultraviolet laser pulsing in the LEAP 5000 XR. We demonstrate that the method that incorporates the temperature-dependent specific heat of Si offers the best approach, which even works in the athermal field-evaporation regime of this material. Apex temperature increases of 51-146 K are found for laser pulse energies of 1-6 pJ at a base temperature of 50 K. The subsequently extracted field-evaporation barrier of (110 ± 10) meV for a field reduction ≳0.9 aligns with field-evaporation model predictions. From the review of the literature across different materials and methods, inconsistent apex temperature estimates between methods based on voltage and laser mode were found. However, a reasonably consistent trend between the laser-induced temperature rise and the zero-barrier evaporation field is observed. This suggests a simplified protocol for estimating the rise in specimen apex temperature with increasing laser energy, potentially offering a straightforward and practical route for broader application in atom probe tomography studies.