NMR Crystallography for inorganic materials

We develop state-of-the-art multinuclear and multidimensional solid-stateNMR spectroscopy that is used in tandem with DFT-calculations and diffraction to investigate the structure and dynamics of inorganic, hybrid and microporous materials. Notably, the combined NMR/DFT approach provides information that is difficult to extract from diffraction data only like isoelectronic substitutions, local disorder, positioning of hydrogens, dynamics.

Solid State Imaging

The application of Magnetic Resonance Imaging (MRI) in rigid solids remains challenging as they usually exhibit short transverse relaxation time and strong line broadening which decreases both the sensitivity and the resolution. Magic Angle Spinning (MAS), which averages anisotropic interactions through a macroscopic rotation of the sample, allows obtaining narrow resonances in the solid-state. We show the potentiality of combining MAS and MRI to perform multi-nuclei (1H, 31P, 27Al…) 3D micro-imaging in rigid solid, at very high magnetic field with greatly improved SNR and spatial resolution when compared to static conditions. We apply this methodology on a wide range of materials: polymers, oxide ceramics, biomaterials and hard tissues with spatial resolutions ranging from 30 to 300 microns, at MAS spinning frequencies up to 20 kHz using classical MRI spin-echo or Zero Echo Time (ZTE) sequences. We also developed in vivo localized spectroscopy to study the metabolic profile of drosophila pathological models.

Structure of Glasses

NMR spectroscopy is applied to the oxide glass structure description at a strong level of details thanks to the development of methods exploring heteronuclear and homonuclear correlations. These structural data are essential to characterize the glass properties like chemical durability, thermal stability or behavior to irradiation. For more fundamental interests, these studies explore the ordering of the molecular network at different scales and allow to investigate new glasses formulation and glass instability domains to promote crystallization or phase separation, as interesting roads for new materials investigation (biomaterials, optical devices..). Ab initio calculations and Molecular Dynamics Simulation are then developed in support of NMR spectra simulation and glass structure interpretation enhancement.

High Temperature

We have developed over the last 30 years home-made NMR probes to investigate in-situ high temperature processes. Using a levitation system inside the NMR probe we investigate the structure and dynamics of molten refractory materials up to 2400°C and in contactless conditions. Under static conditions, we are able to investigate materials contained in sealed crucible up to 1400°C, leading to structural investigations of high-temperature liquids such as molten salts as well as aluminosilicate glasses near their glass transition temperature, using our high-field capabilities (20.0 T). This setup has been implemented inside PFG apparatus, allowing the measurement of self-diffusion coefficient in molten salts. The recent acquisition of a laser-heated MAS probe working on our 17.9 T magnet opens the way to the study of phase, glass and solid/liquid transition up to 700°C.

Materials

The group has acquired a great expertise in the characterization of inorganic and hybrid materials.
He participates in a multidisciplinary approach aimed at the development of innovative biomaterials for bone reconstruction. The problem is as well the improvement of the mechanical properties than the development of materials allowing the vectorization of specific contrast or therapeutics agents.
In the context of building materials, the group is particularly interested in understanding the mechanisms that affect the hydration of different kinds of cement: Portland, sulphoaluminate but also cement-substitute as slag or ashes.
Concerning environmental risk of dust explosion and the very large development observed in the domain of additive layer manufacturing (ALM), NMR analyses are applied to the understanding of the explosion and combustion mechanisms for fine metallic powders.

member of the IR-RMN THC FR3050 CNRS

The delocalized Research Infrastructure "NMR at Very High Fields" (IR-RMN-THC FR3050 CNRS) is a network build on French research teams working with very high fields (typically ≥ 20.0 T) with an internationally recognized expertise. It is part of the the French Research Infrastructure Roadmap.

This network is open to the national, and to a lesser extent international, scientific community of users. It aims at fulfilling the needs of NMR spectroscopists as well as scientist outside of the NMR field. The host laboratories offer access to their state-of-the-art high magnetic field apparatus along with their scientific expertise gained with the most recent technological, methodological and scientific developments in their respective field.

NMR dedicated programs

dmfit program