High-resolution 17O NMR spectroscopy of wadsleyite (β-Mg2SiO4)
High-resolution 17O NMR spectroscopy of wadsleyite (β-Mg2SiO4)
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DOI：
10.1021/ja036777k
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发表时间：
2003-10-01
影响因子：
15
通讯作者：
Wimperis, S
中科院分区：
文献类型：
--
作者：
Ashbrook, SE;Berry, AJ;Wimperis, S
近年来，固体的高分辨率~(17)O(i=5/2)核磁共振波谱的灵敏度有了显著的提高。在这里，我们表明，现在可以从毫克量的富含17O的材料中获得极好的结果，从而使这项技术可以应用于在多个砧座装置中在非常高的压力下合成硅酸盐相。我们首次报道了β-Mg_2SiO_4的17O核磁共振研究(9.6 mg的35%17O富集物，合成的ATP值为16 GPaT=1873K)，这是一种被认为在地幔中具有重要作用的致密相。利用B0=9.4和11.7T磁场下的STMAS和B0=18.8T下的MQMAS，我们对四个不同的O位进行了分辨和归属，并测定了它们的化学位移和四极参数。
The sensitivity of high-resolution17O (I=5/2) NMR spectroscopy of solids has advanced significantly in recent years. Here, we show that excellent results are now obtainable from milligram quantities of17O-enriched materials, thereby allowing the technique to be applied to silicate phases synthesized under very high pressures in a multiple-anvil apparatus. We report the first17O NMR study of β-Mg2SiO4(9.6 mg of 35%17O-enriched material, synthesized atp= 16 GPa andT= 1873 K), a dense phase believed to have a significant role in the Earth's mantle. Using STMAS at magnetic fields ofB0= 9.4 and 11.7 T and MQMAS atB0= 18.8 T, we have resolved and assigned all four crystallographically distinct O sites and determined their chemical shift and quadrupolar parameters.