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WP9 - Enhanced Sensitivity and Single Scan Nuclear Magnetic Resonance (ES3-NMR)

NMR has become the method of choice for many problems in materials science. Subtle changes in the local environment of the nuclei can be studied in great detail. In chemistry one uses NMR to identify for example molecular structure, inter-molecular interactions, active sites in functional materials, the molecular dynamics, diffusion and local order/disorder. In physics NMR is used to study static and dynamic properties of condensed matter, like quantum phase transitions in strongly correlated electron systems, metal-organic and molecular magnets, high-temperature and organic superconductors as well as many other systems in the current focus of material research. Since X-ray and neutron spectroscopy above 17 T are still in their infancy, NMR is currently the only technique that provides microscopic, structural information in higher magnetic fields. In NMR research communities there is a strong drive towards higher magnetic fields. For chemistry related problems a higher magnetic field can substantially enhance both sensitivity and resolution. For many physical problems one can use the magnetic field as an external parameter to induce phase transitions. This provides a strong incentive to extend the NMR technique to the realm of ultra high DC and pulsed magnetic fields. Solid state NMR spectroscopy at the highest available fields is expected to become a key technique for any leading high magnetic field user facility.

High resolution NMR research and development projects are a central and extensive activity at the National High Magnetic Field Laboratory (NHMFL) in Tallahassee (FL) and Los Alamos (NM) and at the Tsukuba Magnet Laboratory in Japan. At present the combined NMR effort of European high field facilities is only a small fraction of the USA or Japanese efforts. In EuroMagNET I, a collaboration was formed to develop the necessary methodology both for high resolution solid state NMR in DC resistive magnets and for exploratory research in pulsed magnetic fields. This has led to major breakthroughs in both areas and proof of principle was obtained for user experiments at the European high magnetic field facilities. In commercial (superconducting magnet) spectrometers, data averaging is used to compensate for the low intrinsic sensitivity of NMR. The energy consumption of high field resistive DC magnets and the low duty cycle of pulsed magnets clearly exclude extensive averaging.

The central task of this JRA is to improve the efficiency of the NMR experiments to reduce measurement time and open up the technique for a wider field of applications, including materials with low natural abundance nuclei, less sensitive (low ) nuclei, strong disorder and systems with very strong (quadrupolar) couplings. The implementation of NMR in high pulsed magnetic field user facilities will create new possibilities in a field of large scientific and technological interest and strengthen Europe’s competitiveness in the field of NMR.

At present, the European high field facilities serve mainly the physical sciences community. A successful implementation of enhanced sensitivity and single scan NMR can make the high field facilities more attractive for the wider research community, in particular for the chemical and bio-chemical sciences.