Decomposition of Fe3S above 250 GPa
Decomposition of Fe3S above 250 GPa
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DOI：
10.1002/grl.50946
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发表时间：
2012-12
影响因子：
5.2
通讯作者：
Haruka Ozawa;K. Hirose;Toshihiro Suzuki;Y. Ohishi;N. Hirao
中科院分区：
文献类型：
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作者：
Haruka Ozawa;K. Hirose;Toshihiro Suzuki;Y. Ohishi;N. Hirao
我们用激光加热的金刚石压腔技术测定了高达271 Gpa的Fe-FeS体系的亚固相线相关系。高温高压下的原位同步X射线衍射仪测量表明，在241 GPa2510K下，六方密堆积Fe和四方Fe3S共存；而250 GPa以上的X射线衍射数据表明，对于三种不同的Fe-S块体成分(10，16和20atm%S)，六方密排Fe相和CsCl(B2)型相共存。此外，用扫描电子显微镜对回收的样品进行的化学分析表明，Fe3S样品在271 Gpa和2530K下分解为两个相，这与X射线衍射数据一致。理论预测，在核心条件下，Fe和FeS之间存在广泛的固溶体，而我们的结果表明，Fe-FeS系统至少在271 GPa时保持共晶。
We have determined subsolidus phase relations in the Fe–FeS system up to 271 GPa using laser‐heated diamond‐anvil cell techniques. In situ synchrotron X‐ray diffraction (XRD) measurements performed at high pressure and high temperature demonstrate the coexistence of hexagonal close‐packed (hcp) Fe and tetragonal Fe3S up to 241 GPa and 2510 K. In contrast, the XRD data obtained above 250 GPa show that the hcp phase coexists with the CsCl (B2)‐type phase for three different Fe–S bulk compositions (10, 16, and 20 atm% S). Furthermore, chemical analyses using a scanning transmission electron microscope on a retrieved sample indicate that Fe3S sample decomposes into two phases at 271 GPa and 2530 K, consistent with the XRD data. Theory predicts the presence of extensive solid solution between Fe and FeS at inner core conditions, whereas our results suggest that the Fe–FeS system remains eutectic at least to 271 GPa.