Carbonates under shock compression: stability, phase transitions, and chemical reactions with silicates

项目05主要研究在15 GPa以上的动态高压作用下碳酸盐的稳定性、相变、高压相的形成和化学反应。在对Ca， Mg和Sr的纯合成碳酸盐进行基础研究之后，将进行CaMg(CO3)2和FeCO3的实验，以及这些碳酸盐与选定的硅酸盐相的混合物的实验。同时，本实验室已经建立的飞板激波法也将得到进一步的发展。为了防止二氧化碳的形成和氧化物在释放路径上与相应的碳酸盐重新结合，我们将使用层压飞片，允许在相对较低的温度下施加100 - 200 GPa的压力，而不会熔化样品。在所有情况下，充分的样品回收提供了一个特别设计的阻抗校正样品容器。这将为使用需要大量分析技术提供机会，例如轻元素（C， O和H）的大量元素分析，粉末xrd与Rietveld分析，固态NMR研究，热分析研究（TG-MS， DTA， DSC）和产品形态研究。此外，产品将使用FOR2125研究单元中用于其他组的金刚石砧细胞样本的（原位）技术进行分析。

The proposed project 05 is focused on the understanding of stabilities, phase transitions, formation of high pressure phases and chemical reactions of carbonates upon application of dynamic high pressures above 15 GPa. After fundamental studies on the pure synthetic carbonates of Ca, Mg and Sr, experiments with CaMg(CO3)2and FeCO3 as well as mixtures of these carbonates with selected silicate phases will follow. In parallel, the flyer-plate shock wave method well established in our laboratory will be further developed. In order to prevent carbon dioxide formation and recombination with oxides to the corresponding carbonates on the release path, we will use laminated flyer-plates allowing to apply pressures of > 200 GPa at relatively low temperatures without melding the specimens. In all cases full sample recovery is provided by an especially designed impedance corrected sample container. This will provide opportunities to use analytical techniques which require larger amounts such as bulk elemental analysis of light elements (C, O and H), powder-XRD with Rietveld analysis, solid-state NMR studies, thermal analysis investigations (TG-MS, DTA, DSC) and studies on the product morphologies. Besides, the products will be analyzed with the (in situ) techniques used for the diamond anvil cell samples of the other groups in the research unit FOR2125.