The hydrogen inventory in plasma exposed graphite surfaces
The hydrogen inventory in plasma exposed graphite surfaces
复制标题
等离子体暴露石墨表面的氢存量
DOI：
10.1016/s0022-3115(96)00746-5
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
B. Scherzer
中科院分区：
文献类型：
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作者：
M. Langhoff;B. Scherzer
研究了射频放电过程中石墨中氢的捕获。采用离子束分析方法对放置在rf反应器壁上的靶材进行了原位研究。在相似能量范围≤200 eV的离子束注入实验中，发现氢库存量是预期的两倍。此外，还观察到高能分析束对离子诱导脱附的增强作用。由此得出结论，富氢C: h层的形成是由热和高能（≤200ev）氢的同时撞击形成的。提出了一个模型，解释了甲基自由基在表面形成的拼接过程中C: h层的形成。在等离子体暴露期间，进行了时间分辨捕获测量，以测试氢的瞬态吸收。在600 K以下没有这种现象。此外，金属杂质导致室温下动态库存的假设也可以被推翻。
The trapping of hydrogen in graphite was investigated during exposure to an rf-discharge. The target placed in the wall ofthe rf-reactor was investigated in-situ by ion beam analysis. The hydrogen inventory was found to be twice as high as expected from ion beam implantation experiments in the similar energy range ≤ 200 eV. Also an enhanced ion induced desorption by the energetic analyzing beam was observed. This leads to the conclusion that a buildup of a hydrogen rich C:H-layer is formed by the simultaneous impact of thermal and energetic (≤ 200 eV) hydrogen. A model is presented which) explains the formation of the C:H-layer by a stitching process of methyl radicals forming on the surface. Time resolved trapping measurements were performed to test for a transient uptake of hydrogen during plasma exposure. No such phenomenon could be detected below 600 K. Also the supposition that metallic impurities are responsible for a dynamic inventory at room temperature could be disproved.