Dynamic polarization of protons, deuterons, and carbon-13 nuclei: thermal contact between nuclear spins and an electron spin-spin interaction reservoir

Hydrogen, deuterium, and carbon-13 nuclear spin systems have been studied in partially deuterated 1,2-ethanediol (CD/sub 2/OH)/sub 2/, doped with paramagnetic Cr/sup V/ complexes, between 0.1 and 0.5K, using the technique of dynamic polarization. Various steady- state and transient measurements demonstrate the existence of a thermal contact between the different spin species of this sample and the electron spin-spin interaction reservoir. The lowest spin temperature attained was about 1.2 mK in a magnetic field of 25 kG, which corresponds to a proton polarization of 97%, to a deuteron polarization of 40%, and to a carbon-13 polarization of 48%. (15 refs).