在-31核磁共振放松过程中的旋转扩散在被偏磁杂质污染的多层晶体α-Sn(IV) 酸盐中
Vladimir I Bakhmutov1, Douglas W Elliott1, Nattamai Bhuvanesh1
1Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA.
旋转扩散到偏磁离子控制-31 T1放松在层叠的锡酸盐. 在相关化合物中使用电子磁共振 (EPR) 和核磁共振 (NMR) 证实了这一发现.
科学领域:
- 固态化学 固态化学
- 核磁共振 (NMR) 谱学是指核磁共振的光谱学.
- 电子偏磁共振 (EPR) 光谱学
背景情况:
- 层状晶体锡酸盐是各种领域潜在应用的材料.
- 了解固态材料中的放松机制对于描述它们的特性至关重要.
- 磁性离子可以显著影响NMR放松时间.
研究的目的:
- 为了研究控制-31 (31P) T1放松的因素在分层的晶体Sn(IV) 酸盐中.
- 确定在这种放松过程中对磁性离子的旋转扩散的作用.
- 量化材料中的旋转-扩散常数.
主要方法:
- 进行了固态核磁共振 (NMR) 实验.
- 测量P T1放松时间作为旋转速率的函数.
- 电子偏磁共振 (EPR) 用于检测偏磁离子.
- 对酸和二磁性化合物 ((NH4)) HPO (4) 进行了比较P T1测量.
主要成果:
- 发现,在分层的Sn (IV) 酸盐中P T1放松完全由对磁性离子的旋转扩散控制.
- 旋转扩散常数 (D(SD)) 估计为2.04 x 10-14 cm2s-1.
- 在酸中观察到类似的偏磁离子影响放松,而二磁性化合物表现出不同的行为.
结论:
- 旋转扩散到偏磁中心是这种多层酸中P T1放松的主要机制.
- 该研究提供了这个材料系统中旋转扩散的定量测量.
- 这些发现强调了在酸盐的固态NMR研究中对磁性杂质的重要性.
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