APT Heating

Project Summary

The atom probe is a unique and powerful instrument that allows for the atom-by-atom reconstruction of a nanomaterial (atom probe tomography, APT). Historically, atom probes were restricted to metallic or conducting materials. However, this restriction was rectified with the addition of a laser pulse to assist in ion evaporation.

The current understanding of how the laser heating of nanomaterials in a laser-assisted atom probe affects the ion evaporation events is lacking. In this research we created a theoretical model to predict the temperature evolution of a laser-pulsed nanowire in order to help elucidate evaporation events in an atom probe/APT.

The framework allows for the prediction of the temperature profile and rates for both uniform and tapered nanowires and various laser pulse periods and wavelengths. In the ‘Related Media’ section below, I’ve included some videos (click on the expandable sections to watch) that show how the polarization of the incident light, as well as the taper angle and crystallinity of the silicon nanowire can change not only the temperature along the length of the nanowire, but also the thermal dissipation once the laser pulse has turned off.

Related Media

Pulsed laser heating of tapered nanowire for APT heating analysis.

Acquired Skills

Theoretical Modelling & Simulation

Pulsed Laser Heating / Time-Dependent Theory
Molecular Dynamic & Density Functional Theory Simulations
Finite-Difference Time-Domain Pulsed Simulations