Control and monitoring of oxygen fugacity in piston cylinder experiments
Control and monitoring of oxygen fugacity in piston cylinder experiments
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DOI：
10.1007/s00410-015-1105-z
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发表时间：
2015-01
影响因子：
3.5
通讯作者：
Vladimir Matjuschkin;R. Brooker;B. Tattitch;J. Blundy;C. C. Stamper-C.
中科院分区：
文献类型：
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作者：
Vladimir Matjuschkin;R. Brooker;B. Tattitch;J. Blundy;C. C. Stamper-C.
我们提出了一种新开发的胶囊设计，解决了高压活塞缸实验中与监测和控制氧逸度 (fO2) 相关的一些常见问题。新的fO2控制组件由一个AuPd外胶囊和两个内胶囊组成：一个AuPd胶囊含有实验电荷（包括一些水），另一个Pt胶囊含有固体氧缓冲剂和水。内胶囊由可压碎的氧化铝分隔。外层胶囊由 Pyrex 套管包围，以同时最大限度地减少电池中的氢损失和石墨炉中的碳渗透。使用此电池设计的受控 fO2 实验在 1.0 GPa 和 1,000 °C 下进行。我们使用压力灵敏度经过良好校准的 NiPd、CoPd 和 (Ni, Mg)OfO2 传感器分别监测 Re-ReO2、Ni-NiO 和 Co-CoO 缓冲实验中实现的氧化还原态。 fO2 传感器的结果与缓冲液建立的预期 fO2 非常一致，证明了 24-48 小时持续时间的出色控制，不确定性小于 ±0.3 log bar 单位。
We present a newly developed capsule design that resolves some common problems associated with the monitoring and control of oxygen fugacity (fO2) in high-pressure piston cylinder experiments. The newfO2control assembly consists of an AuPd outer capsule enclosing two inner capsules: one of AuPd capsule containing the experimental charge (including some water), and the other of Pt containing a solid oxygen buffer plus water. The inner capsules are separated by crushable alumina. The outer capsule is surrounded by a Pyrex sleeve to simultaneously minimise hydrogen loss from the cell and carbon infiltration from the graphite furnace. ControlledfO2experiments using this cell design were carried out at 1.0 GPa and 1,000 °C. We used NiPd, CoPd and (Ni, Mg)OfO2sensors, whose pressure sensitivity is well calibrated, to monitor the redox states achieved in experiments buffered by Re–ReO2, Ni–NiO and Co–CoO, respectively. Results for thefO2sensors are in good agreement with the intendedfO2established by the buffer, demonstrating excellent control for durations of 24–48 h, with uncertainties less than ± 0.3 log bar units offO2.