Effect of sulfur on sound velocity of liquid iron under Martian core conditions
Effect of sulfur on sound velocity of liquid iron under Martian core conditions
复制标题
火星核心条件下硫对铁液声速的影响
DOI：
10.1038/s41467-020-15755-2
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发表时间：
2020
影响因子：
16.6
通讯作者：
H.
中科院分区：
文献类型：
--
作者：
Nishida;K.;Shibazaki;Y.;Terasaki;H.;Higo;Y.;Suzuki;A.;Funamori;N.;and Hirose;H.
硫被认为是火星核心中的主要轻元素，因此Fe-S合金在相关高压和高温下的声速对于解释其地震学数据具有重要意义。本文采用超声脉冲回波重叠法结合Kawai型多砧装置测量了液态Fe、Fe_（80）S_（20）和Fe_（57）S_（43）的压缩声速（VP），最高可达20 GPa，可能对应于火星最上层核的情况。结果表明，在火星整个堆芯压力范围内，液态铁的VP对硫浓度的敏感性最小。因此，将Fe-S液体的地震波速度与未来的观测结果进行比较，将能够判断火星核心是否熔融，是否含有硫以外的杂质元素。
Sulfur has been considered to be a predominant light element in the Martian core, and thus the sound velocity of Fe-S alloys at relevant high pressure and temperature is of great importance to interpret its seismological data. Here we measured the compressional sound velocity (VP) of liquid Fe, Fe80S20and Fe57S43using ultrasonic pulse-echo overlap method combined with a Kawai-type multi-anvil apparatus up to 20 GPa, likely corresponding to the condition at the uppermost core of Mars. The results demonstrate that theVPof liquid iron is least sensitive to its sulfur concentration in the Mars’ whole core pressure range. The comparison of seismic wave speeds of Fe-S liquids with future observations will therefore tell whether the Martian core is molten and contains impurity elements other than sulfur.