Generation of ultra high pressure by the diamond-anvil cell and estimation of temperature of the Earth's core

我们在美国地球物理实验室毛博士领导的小组所用的基础上进行了改进，研制出了一种新的金刚石顶压室。新的顶压室具有更稳定的活塞，适用于在3000-K的高压下进行非常高温的实验。利用该金刚石压腔，我们获得了以下实验结果：对热解石成分进行了高压熔炼实验。结果表明，它的熔化曲线与MORB相似，支持外核温度在4000-K以上。还对热解石成分进行了固相平衡研究。我们发现，在下地幔中，更多的铁被分配到富镁钙钛矿中，这比之前的估计要多。这表明地球下地幔含有更多的镁钙钛矿。在高温高压下，用原位X射线衍射法测定了GeO2的相变。

We developped a new diamond-anvil cell by modification of that used by the group lead by Dr. Mao at the Geophysical Laboratory, US.The new cell has more stable piston, suitable for the very high temperature experiments up to 3000-K at high pressures. Using this diamond-anvil cell, we obtained the experimental results below ; High pressure melting experiments on the pyrolite composition were conducted. The results showed that its melting curve is similar to MORB, supporting that the temperature of outer core is over 4000-K.Subsolidus phase equilibria studies were also done on the pyrolite composition. We found more iron is partitioned into Mg-rich perovskite in the-lower mantle than the earlier estimates. It suggests that the Earth's lower mantle includes more Mg-perovskite. The phase transition in GeO2 was determined by the in-situ X-ray diffraction measurements at high pressure and high temperature.