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 research internship (5-6 months)

Quartz Dissolution Kinetics in Molten Alkali Silicates for Improved Glass Manufacturing

Objective:

The primary objective of this Master M2 internship is to advance our understanding of quartz dissolution kinetics in molten alkali silicates, a fundamental process in glass production. This project is crucial for minimizing heterogeneities, such as solid inclusions, ensuring high-quality flat glass products. Situated at the intersection of physics and materials chemistry, this research bridges academic inquiry with industrial application, contributing to a larger initiative aimed at optimizing glass manufacturing efficiencies. This internship offers a unique opportunity to engage with both theoretical and practical aspects of materials chemistry, providing insights that are directly applicable to industrial practices. By bridging the gap between academic research and industry needs, this project not only enhances the scientific understanding of glass production but also supports the development of more efficient and higher-quality glass manufacturing techniques.

Project Description:

The dissolution of quartz, a key raw material in soda-lime glass production, involves complex interactions that often lead to the formation of refractory mineral defects. This project focuses on the dynamic processes during quartz dissolution, particularly examining the role of various alkali additives. As a trainee, your responsibilities will encompass:
• Investigating the effects of alkali contributions from molten glass on the dissolution rates of silica polymorphs, including quartz, tridymite, and cristobalite.
• Utilizing advanced computational techniques, such as atomistic molecular dynamics, ab initio calculations, and machine learning models, to simulate the quartz digestion process and its interaction with molten glass cations.
• Analyzing the atomic-scale interactions and structural transformations resulting from these processes, aiming to predict and mitigate the formation of solid defects.

Candidate Requirements:

• Currently enrolled as a Master 2 student specializing in physical chemistry.
• Demonstrated interest and foundational knowledge in molecular modeling and simulation.
• Prior experience with molecular dynamics, though not mandatory, will be advantageous.
• Proven ability to work both independently and collaboratively within a research team.
• Strong motivation to tackle complex scientific problems and contribute to cutting-edge research.

Organic compounds in contact with hot lavas

While meteoritic impacts likely delivered diverse organic compounds to the early Earth, the quantities might have been insufficient, and not all organics may have survived the harsh conditions during atmospheric entry. Many of these compounds could have decomposed in the hot, dense atmosphere of the early Hadean. Thus, efficient environmental niches where simple molecules could consistently complexify on a larger scale might have been crucial for the onset of life. Such niches could include volcanic regions and hydrothermal vents, which not only concentrate organics but also provide the energy and mineral catalysts necessary for synthesizing and polymerizing key life-forming molecules. Understanding these processes helps illuminate how life might have arisen on Earth and could arise elsewhere in the universe.

Here, we explore the role of the volcanic systems, which dominated the Hadean surface, in facilitating the formation of the most primitive building blocks of life. Specifically, we focus on the catalytic role of lava surfaces in promoting the fundamental processes of the first carbon polymerization steps (or breakup) of polycyclic aromatic hydrocarbon (PAH) molecules like benzene, naphthalene, anthracene, and phenanthrene. We conduct atomistic simulations based on energy minimization and molecular dynamics. First, we explore the energy landscape described by PAH in contact with the lava surface, the role of various cations, and the electronic interactions between the two entities. Then, we select the most stable configurations and run molecular dynamic simulations. For this, we first fit a machine-learning interatomic potential set, finely tuned to describe this organic-silicate system correctly. Then, we run large-scale machine-learning molecular dynamics simulations over a wide temperature range.

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.

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.

Job openings