The possible dynamic polarization of nuclei by using coal surface paramagnetic centers

Electron paramagnetic resonance spectra of paramagnetic centers on coal surface at 4.2-300 K have been measured when the sample is in contact with 3He, 4He or oxygen gases. At low temperatures the transferred hyperfine interaction was manifested in the case 3He gas. Our experimental data support a possibility of dynamics polarization of nuclei by using coal surface paramagnetic centers. © 2003 Elsevier Science B.V. All rights reserved