Stanislavovas A, Kuzmin V, Safiullin K, Alakshin E, Klochkov A, Kutuzov M, Tagirov M
Institute of Physics, Kazan Federal University, Kazan 420008, Russia.
Metallurg Engineering Ltd., Tallinn 11415, Estonia.
J Phys Condens Matter. 2021 Apr 26;33(19). doi: 10.1088/1361-648X/abe475.
The results ofHe gas pulsed NMR spin-lattice relaxation study in high-porosity (84.9%-97.9%) nematically ordered AlOaerogels at 1.5 and 4.2 K are presented. The linear dependence ofon gas pressure is observed in aerogels that are pre-plated by helium-4. Nitrogen pre-plating prior to helium-4 pre-plating weakly decreases theHe gas spin-lattice relaxation rate. A few possible mechanisms plausibly involved inHe nuclear magnetic relaxation in aerogels are considered. The suggested nuclear spin-lattice relaxation model due to some magnetically 'dirty' aerogel fibers allows to estimate the effective mean free path ofHe atoms in aerogel.
本文给出了在1.5K和4.2K温度下，对高孔隙率（84.9%-97.9%）向列相有序的AlO气凝胶进行氦气脉冲核磁共振自旋晶格弛豫研究的结果。在预先镀有氦-4的气凝胶中观察到了与气体压力的线性关系。在氦-4预镀之前进行氮气预镀会略微降低氦气自旋晶格弛豫率。考虑了一些可能合理地参与气凝胶中氦核磁共振弛豫的机制。由于一些磁性“脏”气凝胶纤维而提出的核自旋晶格弛豫模型，可以估算氦原子在气凝胶中的有效平均自由程。
