Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Dynamic nuclear polarization (DNP) can increase nuclear magnetic resonance signals by several orders of magnitude. We report on 13 C DNP experiments in diamond at 3.4 and 7 T static magnetic fields in a temperature range of 300 to 1.7 K. Nuclear polarization enhancements between 100 and 600 were measured for all temperatures, corresponding to polarizations between 0.1% (300 K) and 38% (1.7 K) at 7 T. A strong temperature dependence of the DNP profiles was observed with broad lines at low temperatures and more structured features at room temperature. Longitudinal-detected electron paramagnetic resonance (EPR) experiments revealed an additional broad temperature-dependent electron line centered around the m I = 0 line of the P1 triplet transitions. This additional electron line leads to an asymmetry of the low-temperature EPR spectrum and might arise from clustered P1 centers or other nitrogen defects in diamond, e.g., N2 or N3 centers, which are known to shorten P1 electronic relaxation times. Our results suggest that nuclei are preferentially polarized via a direct hyperfine mediated polarization transfer, while nuclear spin diffusion in the sample plays a minor role.
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: Luminous Molecular Nanomagnets with Thermal Sensing Properties, Method Development in Solid-State NMR and Dissolution DNP, Towards new generation of MRI with optically hyperpolarized Si nanostructures., Optimizing Magnetic Resonance Based on Effective Hamiltonians, Flagship of Advanced Mathematics for Sensing, Imaging and Modelling
OpenAlex ID: W4411748371