Phase stabilities and spin transitions of Fe3(S1-xPx) at high pressure and its implications in meteorites
Phase stabilities and spin transitions of Fe3(S1-xPx) at high pressure and its implications in meteorites
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DOI：
10.2138/am-2016-5466
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发表时间：
2016-01-01
影响因子：
3.1
通讯作者：
Qin, Shan
中科院分区：
文献类型：
--
作者：
Gu, Tingting;Fei, Yingwei;Qin, Shan
Fe-S-P化合物在许多陨石中被发现，可能是行星核的重要组成部分。本文研究了Fe-3（S，P）固溶体的相稳定性，并在多砧高压下合成了高质量的Fe_3（Si_（13）x）相。在金刚石对顶砧装置上，利用同步辐射X射线衍射和发射光谱对Fe-3（S_（0.51）30.5）的物理性质进行了进一步的研究。随着压力的增加，S在Fe-3（S，P）固溶体中的溶解度增加。合成纯Fe_3S和Fe-3（S_（0.13）P_（0.87））的最低压力分别为21和8 GPa。观察到的不连续性在约18 GPa的晶胞参数是由铁的高自旋到低自旋的转变，由X射线发射光谱数据支持。如果Fe-3（S，P）固溶体存在于自然界中，则硫在Fe-3（S，P）固溶体中的溶解度可以作为一种很好的压力指示剂。
Fe-S-P compounds have been observed in many meteorites and could be the important components in planetary cores. Here we investigated the phase stability of Fe-3(S,P) solid solutions and synthesized high-quality Fe3(Si_ 13x) high-pressure phases in the multi-anvil press. The physical properties of Fe-3(S0.5130.5) were further studied in the diamond-anvil cell by synchrotron X-ray diffraction and emission spectroscopy. The solubility of S in the Fe-3(S,P) solid solution increases with increasing pressure. The minimum pressure to synthesize the pure Fe3S and Fe-3(S0.13P0.87) is about 21 and 8 GPa, respectively. The observed discontinuity in unit-cell parameters at about 18 GPa is caused by the high-spin to low spin transition of iron, supported by X-ray emission spectroscopy data. The sulfur solubility in Fe-3(S,P) solid solutions could be an excellent pressure indicator if such solid solutions are found in nature.