纳米金刚石在静态和魔角旋转状态下的（13）C自旋晶格弛豫
(13)C spin-lattice relaxation in nanodiamonds in static and magic angle spinning regimes.
作者信息
Sergeev N A, Panich A M, Olszewski M, Shenderova O, Goren S D
机构信息
Institute of Physics, University of Szczecin, 70-451 Szczecin, Poland.
Department of Physics, Ben-Gurion University of the Negev, P. O. Box 653, Be'er Sheva 8410501, Israel.
出版信息
Solid State Nucl Magn Reson. 2015 Apr-May;66-67:51-55. doi: 10.1016/j.ssnmr.2014.10.008. Epub 2014 Nov 13.
We report on (13)C nuclear spin-lattice relaxation time (T1) dependence on the magic-angle-spinning (MAS) rate in powder nanodiamond samples. We confirm that the relaxation is caused by interaction of nuclear spins with fluctuating electron spins of localized paramagnetic defects. It was found that T1 is practically not affected by MAS for small particles, while for larger particles with lower defect density T1 is different in static and MAS regimes and reveals elongation with increasing MAS rate. This effect is attributed to suppression of nuclear spin diffusion by MAS. We propose an approach that describes T1 dependence on the MAS rate and allows quantitative analysis of this effect.
我们报道了粉末状纳米金刚石样品中碳-13（¹³C）核自旋-晶格弛豫时间（T1）对魔角旋转（MAS）速率的依赖性。我们证实弛豫是由核自旋与局域顺磁缺陷的波动电子自旋相互作用引起的。研究发现，对于小颗粒，T1实际上不受MAS影响，而对于缺陷密度较低的较大颗粒，T1在静态和MAS状态下有所不同，并且随着MAS速率的增加而延长。这种效应归因于MAS对核自旋扩散的抑制。我们提出了一种方法，该方法描述了T1对MAS速率的依赖性，并允许对这种效应进行定量分析。
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