Anomalous Nuclear Spin-Lattice Relaxation of 3He in Contact with Ordered Al2O3 Aerogel

Spin-lattice relaxation of He-3 in contact with the ordered Al2O3 fiber aerogel has been studied at the temperature of 1.6 K in fields of 0.1-0.5 T by the pulsed nuclear magnetic resonance (NMR) method. An additional mechanism of the relaxation of He-3 in aerogels is found and it is shown that this relaxation mechanism is not associated with the adsorbed layer. A hypothesis about the influence of intrinsic paramagnetic centers on the relaxation of gaseous He-3 is proposed.