Study on local structure of silicate perovskites by NMR spectroscopy

核磁共振波谱研究硅酸盐钙钛矿的局部结构

• 批准号: 11304036
• 负责人: KANZAKI Masami
• 金额: $ 24.92万
• 依托单位: OKAYAMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11304036/
• 关键词: NMR spectroscopy; high pressure mineral; silicate perovskite; local structure; mantle; 高圧結晶化学; ケイ酸塩プロブスカイト; 鉱物物理学; プロトンNMR; 高圧

The results are summarized below.1. Setup of NMR spectrometer: We have introduced a 400MHz solid MAS NMR spectrometer to our institute. Now routine measurements of MAS NMR for ^<29>Si, ^<27>Al, ^<23>Na, ^1H etc are possible. New probe introduced in 2001 allows us to study low frequency nuclei such as ^<25>Mg, and to conduct multi-quantum NMR experiments. The instrument is now open to external researchers for cooperative research projects.2. Ab initio calculation of chemical shifts: Using molecular orbital technique, we have calculated wide varieties of silicate clusters relevant to melt or glass structures. Calculated shifts well reproduced observed chemical shifts. In order to better assignments of NMR spectra, we also calculated experimentally not-well characterized local structures, such as Al triclusters.3. First-principles calculation of electric field gradient (EFG): In order to predict EFG at quadrupolar nuclei such as Al in minerals, first-principles calculations have been conducted. Large EFG in Ca_2Al_2O_5 oxygen-defected perovskite was predicted. For example.4. Structure of hydrous glasses: In order to investigate water and silicate melt interaction, we have studied hydrous melts using ^<29>Si and ^1H MAS NMR and ^1H-^<29>Si CP MAS NMR. The result shows that water causes melt structure polymerize. This is contrary to common observation, and is very important discovery.5. Structure of sulfur-bearing glasses: In order to see how sulfur dissolves in silicate melts, S-bearing glasses were studied by ^<29>Si MAS NMR. When sulfur is added as native S, melt structure was polymerized.6. Hydration of minerals: Hydration processes of forsterite, enstatite and diopside have studied using ^<29>Si and ^1H MAS NMR. We observed polymerization in hydration layer in all systems studied.7. Crystal chemistry of water-silicate interaction: From these studies, we have gained better crystal chemical insights of the interaction between water and silicate.

研究结果如下： 1．核磁共振波谱仪的设置：我所引进了一台400MHz固体MAS核磁共振波谱仪。现在可以对 29 Si、 27 Al、 23 Na、 1 H 等进行MAS NMR的常规测量。 2001年推出的新探针使我们能够研究低频原子核，例如^ 25 Mg，并进行多量子NMR实验。该仪器现已开放给外部研究人员进行合作研究项目。2．化学位移的从头计算：利用分子轨道技术，我们计算了与熔体或玻璃结构相关的各种硅酸盐簇。计算的位移很好地再现了观察到的化学位移。为了更好地分配核磁共振谱，我们还通过实验计算了表征不充分的局部结构，例如Al三团簇。3．电场梯度（EFG）的第一性原理计算：为了预测矿物中Al等四极核的EFG，进行了第一性原理计算。预测Ca_2Al_2O_5氧缺陷钙钛矿中存在大的EFG。例如4。水合玻璃的结构：为了研究水和硅酸盐熔体的相互作用，我们使用^ 29 Si和^ 1 H MAS NMR以及^ 1H-^ 29 Si CP MAS NMR研究了水合熔体。结果表明，水导致熔体结构聚合。这与通常的观察相反，是非常重要的发现。 5．含硫玻璃的结构： 为了了解硫如何溶解在硅酸盐熔体中，通过^ 29 Si MAS NMR研究了含硫玻璃。当硫以天然S的形式添加时，熔体结构发生聚合。6．矿物的水合：使用^ 29 Si和^ 1 H MAS NMR研究了镁橄榄石、顽辉石和透辉石的水合过程。我们在所有研究的系统中观察到水化层的聚合。7．水-硅酸盐相互作用的晶体化学：通过这些研究，我们对水和硅酸盐之间的相互作用获得了更好的晶体化学见解。

项目成果

T. Sekine, M. Tansho and M. Kanzaki,: "^<29>Si magic-angle-spinning nuclear-magnetic-resonance study of spinet-type Si_3N_4"Applied Physics Letters. 78. 3050-3051 (2001)

T. Sekine、M. Tansho 和 M. Kanzaki，：“^<29>尖晶石型 Si_3N_4 的硅魔角自旋核磁共振研究”应用物理快报。

S.Ono, T.Katsura, E.Ito, M.Kanzaki, A.Yoneda, M.J.Walter, S.Urakawa, W.Utsumi, K.Funakoshi: "In situ observation of ilmenite-perovskite phase transition in MgSiO3 using synchrotron radiation"Geophys.Res.Lett.. 28. 835-838 (2001)

S.Ono、T.Katsura、E.Ito、M.Kanzaki、A.Yoneda、M.J.Walter、S.Urakawa、W.Utsumi、K.Funakoshi：“利用同步辐射对 MgSiO3 中钛铁矿-钙钛矿相变进行原位观察

Xue, X., M.Kanzaki: "Ab initio calculation of the 17 O and 1H NMR parameters for various OH groups : Implications to the speciation and dynamics of dissolved water in silicate glasses"Journal of Physical Chemistry B. 105. 3422-3434 (2001)

Xu, X., M.Kanzaki：“从头计算各种 OH 基团的 17 O 和 1H NMR 参数：对硅酸盐玻璃中溶解水的形态和动力学的影响”物理化学杂志 B. 105. 3422-3434

S. Ono, T. Katsura, E.Ito, M. Kanzaki, A. Yoneda, M.J.: "Walter, et al. In situ observation of ilmenite-perovskite phase transition in MgSiO_3 using synchrotron radiation"Geophysical Research Letters. 28. 835-838 (2001)

S. Ono、T. Katsura、E.Ito、M. Kanzaki、A. Yoneda、M.J.：“Walter 等人。使用同步辐射对 MgSiO_3 中钛铁矿-钙钛矿相变进行原位观察”地球物理研究快报。

X.Xue, M.Kanzaki: "An ab initio calculation of the 17O and 1H NMR parameters for various OH groups : Implications to the speciation and dynamics of dissolved water in silicate glasses"J.Phys.chem.B.. 105. 3422-3434 (2001)

X.Xue, M.Kanzaki：“各种 OH 基团的 17O 和 1H NMR 参数的从头计算：对硅酸盐玻璃中溶解水的形态和动力学的影响”J.Phys.chem.B.. 105. 3422