Paramagnetic Materials Studied by ultra-fast ssNMR Spectroscopy

2026-07-22

Paramagnetic materials have found application in various different industries, in particular involving the conversion, the transport, and the storage of energy. The characteristic microscopic feature for the majority of these materials are unpaired electrons that are located at transition metal ions. Such paramagnetic centers are the key element for the macroscopic properties, e.g., reactivity. To understand the function of paramagnetic materials, why they deliver, or fail to deliver the required properties, and eventually to tune their performance, the local atomic structure of the paramagnetic centers must be fully understood. In diamagnetic materials, these structural features typically escape X-ray diffraction (XRD) and electron microscopy (EM), but are readily accessible to solid-state nuclear magnetic resonance (ssNMR). However, the current repertoire of ssNMR methods is not tailored to paramagnetic systems, where metal centers produce large perturbations in the spectrum of the surrounding nuclei and hamper the critical steps of the acquisition of the NMR experiments and the subsequent spectral assignment and interpretation. In this project, we will align modern multi-dimensional ssNMR experiments with ultra-fast magic-angle spinning (MAS). This includes complex radio-frequency irradiation schemes using amplitude and phase modulation, leveraging the unique instrumentation available at the host lab, allowing us to rotate the studied sample at 110,000 times per second or possibly faster. Supported by numerical spin-density-matrix analysis, we will develop a new toolbox of ssNMR methodologies to acquire high-resolution spectra of paramagnetic materials, and thus, precisely determining element-specific NMR parameters. Linking these spectroscopical features to the structure elements from known samples will finally allow us to present the comprehensive characterization of paramagnetic electrode materials, inaccessible by ssNMR to date.

France

2025-10-01