An analytical model accounting for tip shape evolution during atom probe analysis of heterogeneous materials

Area of Science:

• Materials Science
• Surface Physics
• Computational Modeling

Background:

• Field evaporation is critical for understanding material behavior at the nanoscale.
• Modeling layered structures presents challenges due to differing material properties.

Purpose of the Study:

• To develop an analytical model for field evaporation dynamics of thin films on substrates.
• To investigate the influence of differing evaporation fields on tip morphology.
• To provide a theoretical basis for atom probe tomographic reconstruction.

Main Methods:

• Mesoscopic scale modeling of tip shape.
• Analytical derivation of morphological evolution.
• Comparison with finite difference simulations.

Main Results:

• Non-existence of sharp edges is sufficient for deriving morphological evolution.
• Model provides smooth, instantaneous surface representation.
• Agreement with finite difference simulation results.
• Identified a specific evaporation regime for low-field substrates.

Conclusions:

• The developed model accurately describes field evaporation dynamics in layered tips.
• The model's ability to calculate tip volume has implications for atom probe tomography.
• This work advances understanding of surface morphological evolution during evaporation.