Overview

Several openings are available throughout the year, for short research internships at the master level or equivalent. The internships last between 2 and 6 months, and you will receive financial support according to the standard rules and regulations of the university. For all internships, experience with unix/linux and preferably python and solid knowledge of condensed matter physics and chemistry are required. Previous experience with first-principles simulations is preferred.
If you are interested in a Ph.D. position, several fellowships for outstanding students are available, with a typical start in October of each year. Please take your precautions and apply well in advance.
In particular postdoctoral candidates are welcome to apply for Marie-Curie fellowships. Over the year, the success rate has always been very high.

Please verify regularly for new openings and contact me directly for more information.

Master level M2 short research internship

First-priority topics

Diffusion of noble gases in diamond

Diamond is a very hard and strong material, but it is not impermeable. In fact, various volatiles can diffuse through diamond under the right conditions. However, the rate at which these volatile diffuse is relatively slow compared to their diffusion in other materials. In particular, the diffusion of helium or other noble gases in diamond is a relatively slow process. The exact speed at which they diffuse through diamond depends on a variety of factors, including the temperature and pressure of the diamond, the presence of other point defects and impurities, as well as their concentration within the diamond. Once brought to the surface, the diamonds contain important clues about the rate of production of radioactive isotopes of noble gases.

Here we will perform first-principles molecular dynamics simulations and compare them with results from nudge elastic band calculations to estimate the rate of diffusion of He in diamond. We will look at the transport properties as a function of pressure, temperature, and content.

The internship is in collaboration with Martha Pamato (University of Padova). There is a possibility to extend the internship with a PhD degree, funded via the ERC INHERIT project, awarded to Martha Pamato (https://www.unipd.it/en/erc-pamato-inherit).

Modélisation de la dissolution du quartz dans des melts silicatés

CONTEXTE

La dissolution du quartz dans les silicates alcalins fondus est un processus fondamental dans la fabrication du verre. Le quartz, matière première principale du verre sodo-calcique, est un minéral réfractaire qui peut générer des défauts solides. Dans le cadre du procédé de fusion de verre plat, un défi majeur est de minimiser les hétérogénéités, telles que les inclusions solides, pour garantir la qualité du produit final. Ce sujet, au croisement de la recherche en physique et en chimie des matériaux, recherche académique et industrielle, s’inscrit dans un projet plus large qui vise à comprendre la cinétique de dissolution du quartz et le rôle joué par les différents additifs, tels que des métaux alcalins, dans ce processus.

OBJECTIF DU STAGE

En tant que stagiaire, votre mission sera de comprendre l’effet des alcalins apporté par le verre fondu sur la cinétique de dissolution des différents polymorphes de la silice (quartz, tridymite et cristobalite). Des travaux en cours montrent que lors de la digestion du quartz, des transformations en état solide ont lieux et se superposent à la digestion en elle-même. Vous utiliserez des calculs atomistiques de dynamique moléculaire, ab initio et avec des potentiels machine learning, pour modéliser et simuler ce processus complexe. Votre travail permettra de prédire les interactions à l’échelle atomique entre les cations du verre fondu et la silice, ainsi que les changements structuraux résultant de ces interactions.

PROFIL SOUHAITE

• Étudiant en master 2 dans le domaine de la physico-chimie.
• Intérêt marqué pour la modélisation et la simulation moléculaire.
• Première expérience en dynamique moléculaire souhaitée.
• Capacité à travailler de manière autonome et en équipe.
• Motivation à relever des défis scientifiques complexes.

Durée: 6 mois

Other topics

Supercritical state and evaporation in the silica-water system

The aim of this master stage is to analyze a large dataset of ab initio molecular dynamics simulations performed on the SiO₂-H₂O, which is the archetype of all hydrous silicate systems. The simulations span a wide temperature and pressure range that cover the liquid spinodal line, the liquid-vapor equilibrium curve, and the critical point. We will look at the thermodynamic and transport properties as a function of pressure, temperature, and composition. We will analyze in detail the chemical speciation in the fluid. We will monitor the decomposition, the speciation in the gas phase, and the liquid-vapor relations.

The entire analysis is performed using the open-source UMD package (https://tinyurl.com/3ac75mc8), which is developed on site. Depending on the results, further large-scale first-principles molecular dynamics calculations might be necessary.

Comparison of the supercritical state of tectosilicates

We analyze a large dataset of ab initio molecular dynamics simulations performed on silica and feldspars. The simulations span a wide temperature and pressure range that cover the liquid spinodal line, the liquid-vapor equilibrium curve, and the critical point. We will look at the thermodynamic and transport properties as a function of pressure, temperature, and composition. We will analyze in detail the chemical speciation in the fluid. We will monitor the decomposition, the speciation in the gas phase, and the liquid-vapor relations.

Evaporation and condensation of selected refractory minerals

We analyze a large dataset of ab initio molecular dynamics simulations performed on several refractory minerals. We compute the position of the critical points. We analyze in detail the speciation of the vapor phase and the chemistry developing at the liquid-vapor interface. We will look at the thermodynamic and transport properties as a function of pressure, temperature, and composition.

Minerals as new functional materials

We search for new ferroic materials with inspiration from the mineral world. We plan to work on selected sulfide and sulfosalt minerals and check their potential to develop piezoelectricity, ferroelectricity, and/or ferromagnetism. We will compute their static properties, like electronic, magnetic, and elastic. These results provide further constraints and help reduce the initial selection of minerals. In a further step, we compute the dielectric and dynamical properties of the most favorable minerals. The most promising candidates will serve as future starting materials for a campaign of actual synthesis and single-crystal measurements. The simulations will be performed using the ABINIT package and will be run on the machines from the national supercomputer centers.

Theoretical identification of perchlorate minerals on the surface of Mars

The Mars rovers showed the presence of surface mineralogy that in many respects is different from the one on the surface of our planet. In particular, the dry Martian atmosphere favors the development of a series of characteristic minerals, like perchlorates, which are hard to synthesize and stabilize in the Earth’s atmospheric conditions. The presence of perchlorates was suggested by Raman spectrometry.

Here we want to perform a systematic study of the vibrational properties of various perchlorate minerals. We will calculate the Raman and infrared spectra using the density functional perturbation theory as implemented in the ABINIT package. We will identify the representative peaks that can be used in identification, will analyze the displacement patterns associated with the vibrations, and will relate the chemical and hydration variations with changes in the spectra.

The results will be integrated into the WURM database (https://wurm.info/) and made available to the entire community.

Job openings