Searching mineralogy of the Earth's deep interior using a combination of synchrotron radiation and high-pressure technology

在使用烧结金刚石（SD）砧的多砧装置中产生更高压力的技术发展，以及在地幔过渡区P/T条件下高压相声速的精确测量。我们成功地利用SD砧在室温下产生了高达~ 80 GPa的压力，而在与地幔相关的高温下，压力被限制在~ 60 GPa。下地幔条件下地幔矿物中发现了一些新的相变，并在相应的P、T条件下精确测定了这些相变和其他高压相的P- v -T关系。另一方面，在压力至~ 20GPa、温度至~ 1700K的条件下，精确测量了声速，这些条件相当于地幔过渡区中部的深度。使用这种技术；对软锰矿组成中的菱woodite和majorite、多晶MgO和玄武岩组成中的石榴石（majorite + stishovite）进行了测量，为约束地幔过渡区的矿物学和提供了新的自一致压力标度提供了重要的数据集。除了这些研究之外，我们还测试了新生产的纳米聚晶金刚石（HIME-DIA）在高压器件中的性能，发现这种新材料在多砧装置和金刚石砧细胞中具有巨大的潜力，其最高压力分别为~ 110 Gpa和~ 20 Gpa。

Technical developments have been made in producing higher pressures in multianvil apparatus using sintered diamond (SD) anvils and also for precise measurements of sound velocities of high-pressure phases under the P/T conditions of the mantle transition region. We succeeded to produce pressures as high as〜80 GPa at room temperature using SD anvils, while pressures have been limited to〜60 GPa at the high temperatures relevant to the Earth's mantle. Some new phase transitions have been found in mantle minerals under the conditions of the lower mantle, and precise determination of the P-V-T relations of these and other high-pressure phases have been conducted under the corresponding P, T conditions. On the other hand, precise measurements of sound velocities have been made at pressures to〜20GPa and temperatures to〜1700K, equivalent to those of the depths of the middle part of the mantle transition region. Using this technique; measurements on ringwoodite and majorite in a pyrolite composition, polycrystalline MgO, and the garnetite (majorite + stishovite) in a basaltic composition have been made, which provided important data sets to constrain the mineralogy of the mantle transition region and to provide a new self-consistent pressure scale. In addition to these studies, we have tested the performance of the newly produced nano-polycrystalline diamond (HIME-DIA) for high-pressure devices, and found the great potential of this novel material for anvils for both multianvil apparatus and diamond anvil cell, which yielded the highest pressures of〜110 Gpa and〜20 Gpa, respectively.