MNR Spectra of Magma-related Compounds at Their Molten States.

利用^<29>Si、^<27>Al和^<17>O的核磁共振波谱，阐明了作为岩浆模型物质的碱性和碱性铝硅酸盐的结构和动力学性质。采用铂电阻丝、高纯度氧化铝和氧化锆组成的高温核磁共振探针，在布鲁克MSL 200核磁共振光谱仪中从室温至1200℃工作。^<29>的硅酸钠玻璃的硅核磁共振谱由各个硅酸钠网络单元的贡献组成，根据它们的化学位移各向异性的相对差异。光谱在玻璃化转变温度以上变窄。在液体状态下，观察到洛伦兹型的单一而尖锐的轮廓。假设硅酸盐玻璃和熔体中结构单元之间发生交换反应，通过计算机模拟可以理解线形的温度依赖性。交换反应的活化能与粘性流动的活化能基本一致。用于测量^<27>Al和^<17>O的新探针正在建造中。

The purpose of the present study is to elucidate the structure and dynamic properties of alkali and alkalialunino silicates, as model materials of magmas, by means of ^<29>Si, ^<27>Al and ^<17>O NMR spectroscopy.A high temperature NMR probe made of platinum resistance wire, high purity alumina and zirconia was constructed and operated in a Bruker MSL 200 NMR spectrometer from room temperature to 1200 ﾟC.^<29>Si NMR spectra of the sodium silicate glass were composed of contribution from individual silicate network units in accordance with their relative difference of chemical shift anisotropy. The spectra show narrowing above glass transition temperature. In the liquid state a single and sharp profile of Lorentzian type was observed. The temperature dependence of line shape could be understood by computer simulation assuming exchange reaction among structural units in silicate glasses and melts. The activation energy of the exchange reaction coincided with that of viscous flow.The construction of a new probe for measurement of ^<27>Al and ^<17>O is in progress.