AuPdFe ternary solution model and applications to understanding the fO2 of hydrous, high-pressure experiments
AuPdFe ternary solution model and applications to understanding the fO2 of hydrous, high-pressure experiments
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DOI：
10.1007/s00410-010-0497-z
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发表时间：
2010-11-01
影响因子：
3.5
通讯作者：
Grove, Timothy L.
中科院分区：
文献类型：
--
作者：
Barr, Jay A.;Grove, Timothy L.
本研究提供了一个实验校准的平衡常数的AuPdFe合金与含铁的硅酸盐熔体。由于其缓慢的氢扩散性，用于含H2O实验的理想金属胶囊是纯Au。然而，在Au的熔点以上，必须使用其它材料。解决这个问题的方法是使用AuPd合金胶囊。然而，在大多数相关的fO（2）条件下，该合金从共存的硅酸盐熔体中吸收Fe，从而改变了实验装药的整体组成。本研究结合先前的工作对Au-Pd，Pd-Fe，和Au-Fe二元系统开发三元热力学溶液模型AuPdFe。用该溶液模型计算了FeO熔体→ Fe合金+ 1/2 O（2）交换反应的平衡反应系数。采用非理想三元溶液模型，通过分析样品包壳合金和共存液体的成分，可以估算出含水活塞缸实验的fO（2）条件。
This study provides an experimental calibration of the equilibrium constant for AuPdFe alloys with Fe-bearing silicate melts. The ideal metal capsules for H2O-bearing experiments are pure Au, because of its slow hydrogen diffusivity. However, above the melting point of Au, other materials must be used. The solution to this problem is to use AuPd alloy capsules. However, under most relevant fO(2) conditions, this alloy absorbs Fe from the coexisting silicate melt, thus changing the bulk composition of the experimental charge. This study combines previous work on the Au-Pd, Pd-Fe, and Au-Fe binary systems to develop a ternary thermodynamic solution model for AuPdFe. This solution model is used with experiments to calculate an equilibrium reaction coefficient for the FeOmelt -> Fe-alloy + 1/2O(2) exchange reaction. Using a non-ideal ternary solution model, the fO(2) conditions of hydrous, piston cylinder experiments can be estimated by analyzing the sample capsule alloy and the coexisting liquid composition.