[PAST EVENT] CHEMINAR: Bulk Dynamic Nuclear Polarization of 13C-nuclei via P1 Centers in Diamond

September 16, 2022
3pm - 4pm
Integrated Science Center (ISC), Room 1127
540 Landrum Dr
Williamsburg, VA 23185Map this location
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Bulk Dynamic Nuclear Polarization of 13C-nuclei via P1 Centers in Diamond

Electron and nuclear spins in diamond have long coherence and relaxation times at room temperature, making them a promising platform for applications such as biomedical and molecular imaging and nanoscale magnetic field sensing. While the optically-active nitrogen-vacancy (NV) defect has received a great deal of attention, the substitutional nitrogen (or P1) center also exhibits long coherence and relaxation times. These P1 centers are typically present at significantly larger concentrations than NVs, allowing us to explore the role of P1-P1 interactions in mediating dynamic nuclear polarization (DNP). DNP is a method of enhancing the nuclear magnetic resonance (NMR) signal, increasing the NMR signal by several orders of magnitude, and allowing NMR to be much more sensitive.

Here, we show enhancement of natural abundance 13C nuclei found within the diamond, using the unpaired electron of the P1 center in micro-particles, under static conditions at room temperature. We discuss the DNP spectrum, the active many DNP mechanisms in this sample, what we can learn about the diamond powder from DNP, and even how some DNP techniques allow us to control which mechanisms are active.

Dr. Daphna Shimon is a physical chemist specializing in magnetic resonance in the solid-state, and in particular nuclear magnetic resonance (NMR) and dynamic nuclear polarization (DNP), a method of enhancing NMR signal using unpaired electrons and microwave (MW) irradiation. The Shimon Group laboratory at Hebrew University focuses on the study of small molecules on heterogeneous surfaces of porous materials using magnetic resonance techniques. The projects cover different aspects of molecules in porous materials and benefit significantly from the combination of NMR, DNP (using endogenous paramagnetic centers), EPR, and the development of new DNP tools and techniques.