Postdoctoral Researcher – Atom Probe Tomography

Publication Date : 18th of March 2026
Starting Date : as soon as possible
Location: Montreal, QC, Canada
Duration: 1 year (extension based on performance up to 3 years)

We are looking for a Postdoctoral researcher to join the PolyAPT Team.

We are looking for an applicant that has hands-on experience in Focused Ion Beam based preparation of Atom Probe or Transmission Electron Microscopy samples. The successful applicant will be working in the Department of Engineering Physics at Polytechnique Montreal. They will have the opportunity to apply Atom Probe Tomography to a wide range of material systems including semiconductors, quantum materials, metal alloys and biomaterials and are encouraged to develop their own line of research.

The laboratory is equipped with a Cameca Invizo 6000 tool and access to Cryo-, Plasma and Gallium Focused Ion Beam tools for sample preparation as well as a transfer module to exchange samples under Cryo- and vacuum conditions between different tools. The PolyAPT lab maintains and develops a library for APT data analysis written in Python and we welcome applicants with programming skills.

A competitive compensation aligned with the collective agreement of the ASSEP union for postdoctoral fellows is guaranteed to the successful candidate.

Informal enquiries are welcomed and should be directed to: sebastian.koelling@polymtl.ca

Interested applicants may send their CV to: sebastian.koelling@polymtl.ca

Review of applications will begin immediately and continue until the position is filled.

 

The tip-shaped Atom Probe specimen as a Topological Manifold

Master's or PHD projects

Publication Date : 1st of August 2022
Starting Date : Anytime
Location: Worldwide

This project is aimed at students with a solid background in Mathematics or Mathematical Physics and interest in Differential Geometry and Algebraic Topology.

Atom Probe analyses are carried out using a tip-shaped specimen. Ions are removed one by one form the surface of the tip and then projected onto a single-ion detector about one million times the size of the tip. The tomographic data reconstruction is using the impact position on the detector to estimate the ions positions on the tip surface. In the current state-of-the-art model the tip surface as a hemispherical cap. This is clearly not accurate as the density of ions arriving on the detector is far from homogeneous as would be expected for a projection from a hemisphere.

In this project, we aim to utilize the density variations observed on an Atom Probe detector to model the shape of the tip. We aim to find a projection from a two-dimensional manifold onto the detector that is consistent with the observed distribution of density of ions on the detector and see whether it is possible to show that this two-dimensional manifold is a unique solution to the problem.

If you are interested to work on this project, please contact: sebastian.koelling@polymtl.ca

Figure : Desorption map of ions from an Aluminum tip as observed on an Atom Probe detector. The density of ions is clearly non-uniform. Can we model the shape of the tip surface using these data?